diff --git a/client/browser/src/browser-extension/scripts/backgroundPage.main.ts b/client/browser/src/browser-extension/scripts/backgroundPage.main.ts
index c37a379b52e..7f7fc83296d 100644
--- a/client/browser/src/browser-extension/scripts/backgroundPage.main.ts
+++ b/client/browser/src/browser-extension/scripts/backgroundPage.main.ts
@@ -5,7 +5,7 @@ import '../../config/background.entry'
 import '../../shared/polyfills'
 
 import type { Endpoint } from 'comlink'
-import { combineLatest, merge, type Observable, of, Subject, Subscription, timer } from 'rxjs'
+import { combineLatest, merge, type Observable, of, Subject, Subscription, timer, lastValueFrom } from 'rxjs'
 import {
     bufferCount,
     filter,
@@ -238,7 +238,7 @@ async function main(): Promise<void> {
             variables: V
             sourcegraphURL?: string
         }): Promise<GraphQLResult<T>> {
-            return requestGraphQL<T, V>({ request, variables, sourcegraphURL }).toPromise()
+            return lastValueFrom(requestGraphQL<T, V>({ request, variables, sourcegraphURL }))
         },
 
         async notifyRepoSyncError({ sourcegraphURL, hasRepoSyncError }, sender: browser.runtime.MessageSender) {
diff --git a/client/browser/src/end-to-end/github.test.ts b/client/browser/src/end-to-end/github.test.ts
index b09adac2e3f..5814cc7a0aa 100644
--- a/client/browser/src/end-to-end/github.test.ts
+++ b/client/browser/src/end-to-end/github.test.ts
@@ -3,8 +3,8 @@ import assert from 'assert'
 import { startCase } from 'lodash'
 import { describe, it } from 'mocha'
 import type { Target, Page } from 'puppeteer'
-import { fromEvent } from 'rxjs'
-import { first, filter, timeout, mergeMap } from 'rxjs/operators'
+import { firstValueFrom, fromEvent } from 'rxjs'
+import { filter, timeout, mergeMap } from 'rxjs/operators'
 
 import { isDefined } from '@sourcegraph/common'
 import { getConfig } from '@sourcegraph/shared/src/testing/config'
@@ -141,14 +141,13 @@ describe('Sourcegraph browser extension on github.com', function () {
                         let page: Page = driver.page
                         if (new URL(goToDefinitionURL).hostname !== 'github.com') {
                             ;[page] = await Promise.all([
-                                fromEvent<Target>(driver.browser, 'targetcreated')
-                                    .pipe(
+                                firstValueFrom(
+                                    fromEvent<Target>(driver.browser, 'targetcreated').pipe(
                                         timeout(5000),
                                         mergeMap(target => target.page()),
-                                        filter(isDefined),
-                                        first()
+                                        filter(isDefined)
                                     )
-                                    .toPromise(),
+                                ),
                                 driver.page.click('.test-tooltip-go-to-definition'),
                             ])
                         } else {
diff --git a/client/browser/src/shared/cli/search.ts b/client/browser/src/shared/cli/search.ts
index 065f5497d5d..ea1a5bad330 100644
--- a/client/browser/src/shared/cli/search.ts
+++ b/client/browser/src/shared/cli/search.ts
@@ -1,5 +1,4 @@
-import { from } from 'rxjs'
-import { take } from 'rxjs/operators'
+import { firstValueFrom } from 'rxjs'
 
 import { type ErrorLike, isErrorLike, isDefined, isNot } from '@sourcegraph/common'
 import type { Settings } from '@sourcegraph/shared/src/settings/settings'
@@ -22,7 +21,7 @@ export class SearchCommand {
     private prev: { query: string; suggestions: browser.omnibox.SuggestResult[] } = { query: '', suggestions: [] }
 
     public getSuggestions = async (query: string): Promise<browser.omnibox.SuggestResult[]> => {
-        const sourcegraphURL = await observeSourcegraphURL(IS_EXTENSION).pipe(take(1)).toPromise()
+        const sourcegraphURL = await firstValueFrom(observeSourcegraphURL(IS_EXTENSION))
         return new Promise(resolve => {
             if (this.prev.query === query) {
                 resolve(this.prev.suggestions)
@@ -54,7 +53,7 @@ export class SearchCommand {
         disposition?: 'newForegroundTab' | 'newBackgroundTab' | 'currentTab',
         currentTabId?: number
     ): Promise<void> => {
-        const sourcegraphURL = await observeSourcegraphURL(IS_EXTENSION).pipe(take(1)).toPromise()
+        const sourcegraphURL = await firstValueFrom(observeSourcegraphURL(IS_EXTENSION))
 
         const [patternType, caseSensitive] = await this.getDefaultSearchSettings(sourcegraphURL)
 
@@ -121,7 +120,7 @@ export class SearchCommand {
                 )
 
                 await platformContext.refreshSettings()
-                const settings = (await from(platformContext.settings).pipe(take(1)).toPromise()).final
+                const settings = (await firstValueFrom(platformContext.settings)).final
 
                 if (isDefined(settings) && isNot<ErrorLike | Settings, ErrorLike>(isErrorLike)(settings)) {
                     this.defaultPatternType =
diff --git a/client/browser/src/shared/code-hosts/gitlab/codeHost.ts b/client/browser/src/shared/code-hosts/gitlab/codeHost.ts
index 4f0d70f314a..d044435be1d 100644
--- a/client/browser/src/shared/code-hosts/gitlab/codeHost.ts
+++ b/client/browser/src/shared/code-hosts/gitlab/codeHost.ts
@@ -1,6 +1,6 @@
 import * as Sentry from '@sentry/browser'
 import classNames from 'classnames'
-import { fromEvent } from 'rxjs'
+import { fromEvent, lastValueFrom } from 'rxjs'
 import { filter, map, mapTo, tap } from 'rxjs/operators'
 import type { Omit } from 'utility-types'
 
@@ -286,25 +286,25 @@ export const gitlabCodeHost = subtypeOf<CodeHost>()({
     ),
 
     prepareCodeHost: async requestGraphQL =>
-        requestGraphQL<ResolveRepoNameResult, ResolveRepoNameVariables>({
-            request: gql`
-                query ResolveRepoName($cloneURL: String!) {
-                    repository(cloneURL: $cloneURL) {
-                        name
+        lastValueFrom(
+            requestGraphQL<ResolveRepoNameResult, ResolveRepoNameVariables>({
+                request: gql`
+                    query ResolveRepoName($cloneURL: String!) {
+                        repository(cloneURL: $cloneURL) {
+                            name
+                        }
                     }
-                }
-            `,
-            variables: {
-                cloneURL: getGitlabRepoURL(),
-            },
-            mightContainPrivateInfo: true,
-        })
-            .pipe(
+                `,
+                variables: {
+                    cloneURL: getGitlabRepoURL(),
+                },
+                mightContainPrivateInfo: true,
+            }).pipe(
                 map(dataOrThrowErrors),
                 tap(({ repository }) => {
                     repoNameOnSourcegraph.next(repository?.name ?? '')
                 }),
                 mapTo(true)
             )
-            .toPromise(),
+        ),
 })
diff --git a/client/browser/src/shared/code-hosts/phabricator/backend.tsx b/client/browser/src/shared/code-hosts/phabricator/backend.tsx
index 70a43f30440..140b9df957d 100644
--- a/client/browser/src/shared/code-hosts/phabricator/backend.tsx
+++ b/client/browser/src/shared/code-hosts/phabricator/backend.tsx
@@ -1,4 +1,4 @@
-import { from, type Observable, of, throwError } from 'rxjs'
+import { from, type Observable, of, throwError, lastValueFrom } from 'rxjs'
 import { fromFetch } from 'rxjs/fetch'
 import { map, mapTo, switchMap, catchError } from 'rxjs/operators'
 
@@ -275,9 +275,9 @@ export function getRepoDetailsFromCallsign(
  * case it fails we query the conduit API.
  */
 export function getSourcegraphURLFromConduit(): Promise<string> {
-    return queryConduitHelper<{ url: string }>('/api/sourcegraph.configuration', {})
-        .pipe(map(({ url }) => url))
-        .toPromise()
+    return lastValueFrom(
+        queryConduitHelper<{ url: string }>('/api/sourcegraph.configuration', {}).pipe(map(({ url }) => url))
+    )
 }
 
 const getRepoDetailsFromRepoPHID = memoizeObservable(
diff --git a/client/browser/src/shared/code-hosts/phabricator/fileInfo.test.ts b/client/browser/src/shared/code-hosts/phabricator/fileInfo.test.ts
index 0ce991d0f77..ae5b1ee1910 100644
--- a/client/browser/src/shared/code-hosts/phabricator/fileInfo.test.ts
+++ b/client/browser/src/shared/code-hosts/phabricator/fileInfo.test.ts
@@ -1,5 +1,5 @@
 import { readFile } from 'mz/fs'
-import { type Observable, throwError, of } from 'rxjs'
+import { type Observable, throwError, of, lastValueFrom } from 'rxjs'
 import { beforeEach, describe, expect, test } from 'vitest'
 
 import { resetAllMemoizationCaches } from '@sourcegraph/common'
@@ -145,15 +145,17 @@ const resolveFileInfoFromFixture = async (
     if (!codeView) {
         throw new Error(`Code view matching selector ${codeViewSelector} not found`)
     }
-    return resolver(
-        codeView as HTMLElement,
-        mockRequestGraphQL({
-            ...DEFAULT_GRAPHQL_RESPONSES,
-            ...graphQLResponseMap,
-        }),
-        mockQueryConduit(conduitResponseMap),
-        new URL(url)
-    ).toPromise()
+    return lastValueFrom(
+        resolver(
+            codeView as HTMLElement,
+            mockRequestGraphQL({
+                ...DEFAULT_GRAPHQL_RESPONSES,
+                ...graphQLResponseMap,
+            }),
+            mockQueryConduit(conduitResponseMap),
+            new URL(url)
+        )
+    )
 }
 
 describe('Phabricator file info', () => {
diff --git a/client/browser/src/shared/code-hosts/shared/codeHost.tsx b/client/browser/src/shared/code-hosts/shared/codeHost.tsx
index 32f2a42198c..75809864a92 100644
--- a/client/browser/src/shared/code-hosts/shared/codeHost.tsx
+++ b/client/browser/src/shared/code-hosts/shared/codeHost.tsx
@@ -18,6 +18,7 @@ import {
     concat,
     BehaviorSubject,
     fromEvent,
+    lastValueFrom,
 } from 'rxjs'
 import {
     catchError,
@@ -643,10 +644,12 @@ const isSafeToContinueCodeIntel = async ({
 
         rawRepoName = context.rawRepoName
 
-        const isRepoCloned = await resolvePrivateRepo({
-            rawRepoName,
-            requestGraphQL,
-        }).toPromise()
+        const isRepoCloned = await lastValueFrom(
+            resolvePrivateRepo({
+                rawRepoName,
+                requestGraphQL,
+            })
+        )
 
         return isRepoCloned
     } catch (error) {
diff --git a/client/browser/src/shared/code-hosts/shared/codeViews.test.ts b/client/browser/src/shared/code-hosts/shared/codeViews.test.ts
index a66b8dfd844..7e5249e1df4 100644
--- a/client/browser/src/shared/code-hosts/shared/codeViews.test.ts
+++ b/client/browser/src/shared/code-hosts/shared/codeViews.test.ts
@@ -1,4 +1,4 @@
-import { of } from 'rxjs'
+import { lastValueFrom, of } from 'rxjs'
 import { toArray } from 'rxjs/operators'
 import * as sinon from 'sinon'
 import type { Omit } from 'utility-types'
@@ -33,14 +33,14 @@ describe('codeViews', () => {
             element.className = 'test-code-view'
             document.body.append(element)
             const selector = '.test-code-view'
-            const detected = await of([{ addedNodes: [document.body], removedNodes: [] }])
-                .pipe(
+            const detected = await lastValueFrom(
+                of([{ addedNodes: [document.body], removedNodes: [] }]).pipe(
                     trackCodeViews({
                         codeViewResolvers: [toCodeViewResolver(selector, codeViewSpec)],
                     }),
                     toArray()
                 )
-                .toPromise()
+            )
             expect(detected.map(({ subscriptions, ...rest }) => rest)).toEqual([{ ...codeViewSpec, element }])
         })
         it('should detect added code views from resolver', async () => {
@@ -49,14 +49,14 @@ describe('codeViews', () => {
             document.body.append(element)
             const selector = '.test-code-view'
             const resolveView = sinon.spy((element: HTMLElement) => ({ element, ...codeViewSpec }))
-            const detected = await of([{ addedNodes: [document.body], removedNodes: [] }])
-                .pipe(
+            const detected = await lastValueFrom(
+                of([{ addedNodes: [document.body], removedNodes: [] }]).pipe(
                     trackCodeViews({
                         codeViewResolvers: [{ selector, resolveView }],
                     }),
                     toArray()
                 )
-                .toPromise()
+            )
             expect(detected.map(({ subscriptions, ...rest }) => rest)).toEqual([{ ...codeViewSpec, element }])
             sinon.assert.calledOnce(resolveView)
             sinon.assert.calledWith(resolveView, element)
diff --git a/client/browser/src/shared/code-hosts/shared/views.test.ts b/client/browser/src/shared/code-hosts/shared/views.test.ts
index afa64df04e6..2bd7bf32b15 100644
--- a/client/browser/src/shared/code-hosts/shared/views.test.ts
+++ b/client/browser/src/shared/code-hosts/shared/views.test.ts
@@ -1,5 +1,5 @@
 import { noop } from 'lodash'
-import { from, type Observable, of, Subject, Subscription, NEVER } from 'rxjs'
+import { from, type Observable, of, Subject, Subscription, NEVER, lastValueFrom } from 'rxjs'
 import { bufferCount, map, switchMap, toArray } from 'rxjs/operators'
 import * as sinon from 'sinon'
 import { afterAll, beforeEach, describe, expect, test } from 'vitest'
@@ -40,9 +40,9 @@ describe('trackViews()', () => {
 
     test('detects all views on the page', async () => {
         const mutations: Observable<MutationRecordLike[]> = of([{ addedNodes: [document.body], removedNodes: [] }])
-        const views = await mutations
-            .pipe(trackViews([{ selector: '.view', resolveView: element => ({ element }) }]), toArray())
-            .toPromise()
+        const views = await lastValueFrom(
+            mutations.pipe(trackViews([{ selector: '.view', resolveView: element => ({ element }) }]), toArray())
+        )
         expect(views.map(({ element }) => element.id)).toEqual(['view1', 'view2', 'view3'])
     })
 
@@ -51,13 +51,13 @@ describe('trackViews()', () => {
             { addedNodes: [document.querySelector<HTMLElement>('#view1')!], removedNodes: [] },
         ])
         expect(
-            await mutations
-                .pipe(
+            await lastValueFrom(
+                mutations.pipe(
                     trackViews([{ selector: '.view', resolveView: element => ({ element }) }]),
                     map(({ element }) => element.id),
                     toArray()
                 )
-                .toPromise()
+            )
         ).toEqual(['view1'])
     })
 
@@ -66,13 +66,13 @@ describe('trackViews()', () => {
             { addedNodes: [document.querySelector<HTMLElement>('#view1')!], removedNodes: [] },
         ])
         expect(
-            await mutations
-                .pipe(
+            await lastValueFrom(
+                mutations.pipe(
                     trackViews([{ selector: '.view', resolveView: element => ({ element }) }]),
                     map(({ element }) => element.id),
                     toArray()
                 )
-                .toPromise()
+            )
         ).toEqual(['view1'])
     })
 
@@ -82,8 +82,8 @@ describe('trackViews()', () => {
         selectorTarget.className = 'selector-target'
         document.querySelector<HTMLElement>('#view1')!.append(selectorTarget)
         expect(
-            await mutations
-                .pipe(
+            await lastValueFrom(
+                mutations.pipe(
                     trackViews([
                         {
                             selector: '.selector-target',
@@ -93,15 +93,15 @@ describe('trackViews()', () => {
                     map(({ element }) => element.id),
                     toArray()
                 )
-                .toPromise()
+            )
         ).toEqual(['view1'])
     })
 
     test("doesn't emit duplicate views", async () => {
         const mutations: Observable<MutationRecordLike[]> = of([{ addedNodes: [document.body], removedNodes: [] }])
         expect(
-            await mutations
-                .pipe(
+            await lastValueFrom(
+                mutations.pipe(
                     trackViews([
                         {
                             selector: '.view',
@@ -113,7 +113,7 @@ describe('trackViews()', () => {
                     map(({ element }) => element.id),
                     toArray()
                 )
-                .toPromise()
+            )
         ).toEqual(['view1'])
     })
 
@@ -190,20 +190,20 @@ describe('trackViews()', () => {
             [{ addedNodes: [], removedNodes: [document.querySelector<HTMLElement>('#view1')!] }],
             [{ addedNodes: [], removedNodes: [document.querySelector<HTMLElement>('#view3')!] }],
         ])
-        await mutations
-            .pipe(
+        await lastValueFrom(
+            mutations.pipe(
                 trackViews([{ selector: '.view', resolveView: element => ({ element }) }]),
                 bufferCount(3),
                 switchMap(async ([view1, view2, view3]) => {
                     const v2Removed = sinon.spy(() => undefined)
                     view2.subscriptions.add(v2Removed)
-                    const v1Removed = new Promise(resolve => view1.subscriptions.add(resolve))
-                    const v3Removed = new Promise(resolve => view3.subscriptions.add(resolve))
+                    const v1Removed = new Promise<void>(resolve => view1.subscriptions.add(resolve))
+                    const v3Removed = new Promise<void>(resolve => view3.subscriptions.add(resolve))
                     await Promise.all([v1Removed, v3Removed])
                     sinon.assert.notCalled(v2Removed)
                 })
             )
-            .toPromise()
+        )
     })
 
     test('removes all nested views', async () => {
@@ -211,15 +211,15 @@ describe('trackViews()', () => {
             [{ addedNodes: [document.body], removedNodes: [] }],
             [{ addedNodes: [], removedNodes: [document.querySelector<HTMLElement>('#parent')!] }],
         ])
-        await mutations
-            .pipe(
+        await lastValueFrom(
+            mutations.pipe(
                 trackViews([{ selector: '.view', resolveView: element => ({ element }) }]),
                 bufferCount(3),
                 switchMap(views =>
-                    Promise.all(views.map(view => new Promise(resolve => view.subscriptions.add(resolve))))
+                    Promise.all(views.map(view => new Promise<void>(resolve => view.subscriptions.add(resolve))))
                 )
             )
-            .toPromise()
+        )
     })
 
     test('removes a view without depending on its resolver', async () => {
@@ -259,7 +259,7 @@ describe('trackViews()', () => {
         expect(resolver.resolveView(testElement)).toBe(null)
 
         // Verify that the code view still gets removed.
-        const unsubscribed = new Promise(resolve => view.subscriptions.add(resolve))
+        const unsubscribed = new Promise<void>(resolve => view.subscriptions.add(resolve))
         mutations.next([{ addedNodes: [], removedNodes: [testElement] }])
         await unsubscribed
     })
diff --git a/client/browser/src/shared/extensionHostWorker.ts b/client/browser/src/shared/extensionHostWorker.ts
index 1c6862f9bad..35ccce4478b 100644
--- a/client/browser/src/shared/extensionHostWorker.ts
+++ b/client/browser/src/shared/extensionHostWorker.ts
@@ -1,7 +1,6 @@
 import '@sourcegraph/shared/src/polyfills'
 
-import { fromEvent } from 'rxjs'
-import { take } from 'rxjs/operators'
+import { firstValueFrom, fromEvent } from 'rxjs'
 
 import { hasProperty, logger } from '@sourcegraph/common'
 import { startExtensionHost } from '@sourcegraph/shared/src/api/extension/extensionHost'
@@ -24,7 +23,7 @@ const isInitMessage = (value: unknown): value is InitMessage =>
  */
 async function extensionHostMain(): Promise<void> {
     try {
-        const event = await fromEvent<MessageEvent>(self, 'message').pipe(take(1)).toPromise()
+        const event = await firstValueFrom(fromEvent<MessageEvent>(self, 'message'))
         if (!isInitMessage(event.data)) {
             throw new Error('First message event in extension host worker was not a well-formed InitMessage')
         }
diff --git a/client/browser/src/shared/platform/context.ts b/client/browser/src/shared/platform/context.ts
index 8a526d2b820..68bc573bcfa 100644
--- a/client/browser/src/shared/platform/context.ts
+++ b/client/browser/src/shared/platform/context.ts
@@ -1,4 +1,4 @@
-import { combineLatest, ReplaySubject } from 'rxjs'
+import { combineLatest, lastValueFrom, ReplaySubject } from 'rxjs'
 import { map } from 'rxjs/operators'
 
 import { asError } from '@sourcegraph/common'
@@ -77,7 +77,7 @@ export function createPlatformContext(
         ),
         refreshSettings: async () => {
             try {
-                const settings = await fetchViewerSettings(requestGraphQL).toPromise()
+                const settings = await lastValueFrom(fetchViewerSettings(requestGraphQL))
                 updatedViewerSettings.next(settings)
             } catch (error) {
                 if (isHTTPAuthError(error)) {
diff --git a/client/build-config/src/esbuild/packageResolutionPlugin.ts b/client/build-config/src/esbuild/packageResolutionPlugin.ts
index 77041d4f03a..68c1207702e 100644
--- a/client/build-config/src/esbuild/packageResolutionPlugin.ts
+++ b/client/build-config/src/esbuild/packageResolutionPlugin.ts
@@ -51,14 +51,3 @@ export const packageResolutionPlugin = (resolutions: Resolutions): esbuild.Plugi
         build.onLoad({ filter: new RegExp(''), namespace: 'devnull' }, () => ({ contents: '' }))
     },
 })
-
-export const RXJS_RESOLUTIONS: Resolutions = {
-    // Needed because imports of rxjs/internal/... actually import a different variant of
-    // rxjs in the same package, which leads to observables from combineLatestOrDefault (and
-    // other places that use rxjs/internal/...) not being cross-compatible. See
-    // https://stackoverflow.com/questions/53758889/rxjs-subscribeto-js-observable-check-works-in-chrome-but-fails-in-chrome-incogn.
-    'rxjs/internal/OuterSubscriber': require.resolve('rxjs/_esm5/internal/OuterSubscriber'),
-    'rxjs/internal/util/subscribeToResult': require.resolve('rxjs/_esm5/internal/util/subscribeToResult'),
-    'rxjs/internal/util/subscribeToArray': require.resolve('rxjs/_esm5/internal/util/subscribeToArray'),
-    'rxjs/internal/Observable': require.resolve('rxjs/_esm5/internal/Observable'),
-}
diff --git a/client/build-config/src/esbuild/workerPlugin.ts b/client/build-config/src/esbuild/workerPlugin.ts
index 99cb4e64a01..969ab813f9e 100644
--- a/client/build-config/src/esbuild/workerPlugin.ts
+++ b/client/build-config/src/esbuild/workerPlugin.ts
@@ -1,6 +1,6 @@
 import type * as esbuild from 'esbuild'
 
-import { packageResolutionPlugin, RXJS_RESOLUTIONS } from './packageResolutionPlugin'
+import { packageResolutionPlugin } from './packageResolutionPlugin'
 
 /**
  * Starts a new esbuild build to create a bundle for a Web Worker.
@@ -21,7 +21,6 @@ async function buildWorker(
         plugins: [
             packageResolutionPlugin({
                 path: require.resolve('path-browserify'),
-                ...RXJS_RESOLUTIONS,
             }),
         ],
         // Use the minify option as an indicator for running in dev mode.
diff --git a/client/codeintellify/src/helpers.ts b/client/codeintellify/src/helpers.ts
index 03b2dfd7edd..d201f213ccf 100644
--- a/client/codeintellify/src/helpers.ts
+++ b/client/codeintellify/src/helpers.ts
@@ -1,5 +1,5 @@
 import { isObject } from 'lodash'
-import { type Subscribable, type Observable, from } from 'rxjs'
+import { type Observable, from } from 'rxjs'
 import { map } from 'rxjs/operators'
 
 import { isDefined } from '@sourcegraph/common'
@@ -17,9 +17,9 @@ const isPromiseLike = (value: unknown): value is PromiseLike<unknown> =>
  * single result, to the same type.
  */
 export const toMaybeLoadingProviderResult = <T>(
-    value: Subscribable<MaybeLoadingResult<T>> | PromiseLike<T>
+    value: Observable<MaybeLoadingResult<T>> | PromiseLike<T>
 ): Observable<MaybeLoadingResult<T>> =>
-    isPromiseLike(value) ? from(value).pipe(map(result => ({ isLoading: false, result }))) : from(value)
+    isPromiseLike(value) ? from(value).pipe(map(result => ({ isLoading: false, result }))) : value
 
 /**
  * Returns a function that returns `true` if the given `key` of the object is not `null` or `undefined`.
diff --git a/client/codeintellify/src/hoverifier.test.ts b/client/codeintellify/src/hoverifier.test.ts
index 938a839e5d1..57e7fa507f1 100644
--- a/client/codeintellify/src/hoverifier.test.ts
+++ b/client/codeintellify/src/hoverifier.test.ts
@@ -2,7 +2,7 @@ import { isEqual } from 'lodash'
 import { EMPTY, NEVER, of, Subject, Subscription } from 'rxjs'
 import { delay, distinctUntilChanged, filter, first, map, takeWhile } from 'rxjs/operators'
 import { TestScheduler } from 'rxjs/testing'
-import { afterAll, afterEach, beforeAll, describe, it, expect } from 'vitest'
+import { afterEach, beforeEach, describe, it, expect } from 'vitest'
 
 import { isDefined } from '@sourcegraph/common'
 import type { Range } from '@sourcegraph/extension-api-types'
@@ -27,17 +27,18 @@ import {
 import { dispatchMouseEventAtPositionImpure } from './testutils/mouse'
 
 describe('Hoverifier', () => {
-    const dom = new DOM()
-    afterAll(dom.cleanup)
-
+    let dom: DOM
     let testcases: CodeViewProps[] = []
-    beforeAll(() => {
+
+    beforeEach(() => {
+        dom = new DOM()
         testcases = dom.createCodeViews()
     })
 
     let subscriptions = new Subscription()
 
     afterEach(() => {
+        dom.cleanup()
         subscriptions.unsubscribe()
         subscriptions = new Subscription()
     })
diff --git a/client/codeintellify/src/hoverifier.ts b/client/codeintellify/src/hoverifier.ts
index 2f9c6a3aaae..2a2be5daa22 100644
--- a/client/codeintellify/src/hoverifier.ts
+++ b/client/codeintellify/src/hoverifier.ts
@@ -11,11 +11,10 @@ import {
     type Observable,
     of,
     Subject,
-    type Subscribable,
-    type SubscribableOrPromise,
     Subscription,
     race,
     type MonoTypeOperatorFunction,
+    ObservableInput,
 } from 'rxjs'
 import {
     catchError,
@@ -75,7 +74,7 @@ export interface HoverifierOptions<C extends object, D, A> {
     /**
      * Emit the HoverOverlay element on this after it was rerendered when its content changed and it needs to be repositioned.
      */
-    hoverOverlayRerenders: Subscribable<{
+    hoverOverlayRerenders: ObservableInput<{
         /**
          * The HoverOverlay element
          */
@@ -89,13 +88,13 @@ export interface HoverifierOptions<C extends object, D, A> {
 
     pinOptions?: {
         /** Emit on this Observable to pin the popover. */
-        pins: Subscribable<void>
+        pins: ObservableInput<void>
 
         /** * Emit on this Observable when the close button in the HoverOverlay was clicked */
-        closeButtonClicks: Subscribable<void>
+        closeButtonClicks: ObservableInput<void>
     }
 
-    hoverOverlayElements: Subscribable<HTMLElement | null>
+    hoverOverlayElements: ObservableInput<HTMLElement | null>
 
     /**
      * Called to get the data to display in the hover.
@@ -199,7 +198,7 @@ export interface AdjustPositionProps<C extends object> {
  *
  * @template C Extra context for the hovered token.
  */
-export type PositionAdjuster<C extends object> = (props: AdjustPositionProps<C>) => SubscribableOrPromise<Position>
+export type PositionAdjuster<C extends object> = (props: AdjustPositionProps<C>) => ObservableInput<Position>
 
 /**
  * HoverifyOptions that need to be included internally with every event
@@ -235,13 +234,13 @@ export interface EventOptions<C extends object> {
  */
 export interface HoverifyOptions<C extends object>
     extends Pick<EventOptions<C>, Exclude<keyof EventOptions<C>, 'codeViewId'>> {
-    positionEvents: Subscribable<PositionEvent>
+    positionEvents: ObservableInput<PositionEvent>
 
     /**
      * Emit on this Observable to trigger the overlay on a position in this code view.
      * This Observable is intended to be used to trigger a Hover after a URL change with a position.
      */
-    positionJumps?: Subscribable<PositionJump>
+    positionJumps?: ObservableInput<PositionJump>
 }
 
 /**
@@ -388,7 +387,7 @@ export const MOUSEOVER_DELAY = 50
  */
 export type HoverProvider<C extends object, D> = (
     position: HoveredToken & C
-) => Subscribable<MaybeLoadingResult<(HoverAttachment & D) | null>> | PromiseLike<(HoverAttachment & D) | null>
+) => Observable<MaybeLoadingResult<(HoverAttachment & D) | null>> | PromiseLike<(HoverAttachment & D) | null>
 
 /**
  * Function that returns a Subscribable or PromiseLike of the ranges to be highlighted in the document.
@@ -399,13 +398,13 @@ export type HoverProvider<C extends object, D> = (
  */
 export type DocumentHighlightProvider<C extends object> = (
     position: HoveredToken & C
-) => Subscribable<DocumentHighlight[]> | PromiseLike<DocumentHighlight[]>
+) => ObservableInput<DocumentHighlight[]>
 
 /**
  * @template C Extra context for the hovered token.
  * @template A The type of an action.
  */
-export type ActionsProvider<C extends object, A> = (position: HoveredToken & C) => SubscribableOrPromise<A[] | null>
+export type ActionsProvider<C extends object, A> = (position: HoveredToken & C) => ObservableInput<A[] | null>
 
 /**
  * Function responsible for resolving the position of a hovered token
@@ -1050,7 +1049,9 @@ export function createHoverifier<C extends object, D, A>({
     }
 
     // Pin on request.
-    subscription.add(pinOptions?.pins.subscribe(() => container.update({ pinned: true })))
+    if (pinOptions) {
+        subscription.add(from(pinOptions.pins).subscribe(() => container.update({ pinned: true })))
+    }
 
     // Unpin on close, ESC, or click.
     subscription.add(
diff --git a/client/codeintellify/src/positions.ts b/client/codeintellify/src/positions.ts
index 4dd53a5cf4d..5f071787fc0 100644
--- a/client/codeintellify/src/positions.ts
+++ b/client/codeintellify/src/positions.ts
@@ -1,4 +1,4 @@
-import { from, fromEvent, merge, type Observable, type Subscribable } from 'rxjs'
+import { from, fromEvent, merge, type Observable } from 'rxjs'
 import { filter, map, switchMap, tap } from 'rxjs/operators'
 
 import { convertCodeElementIdempotent, type DOMFunctions, type HoveredToken, locateTarget } from './tokenPosition'
@@ -28,7 +28,7 @@ export interface PositionEvent {
 
 export const findPositionsFromEvents =
     ({ domFunctions, tokenize = true }: { domFunctions: DOMFunctions; tokenize?: boolean }) =>
-    (elements: Subscribable<HTMLElement>): Observable<PositionEvent> =>
+    (elements: Observable<HTMLElement>): Observable<PositionEvent> =>
         merge(
             from(elements).pipe(
                 switchMap(element =>
diff --git a/client/codeintellify/src/testutils/fixtures.ts b/client/codeintellify/src/testutils/fixtures.ts
index 7cb08ad455c..6b24bc8a76c 100644
--- a/client/codeintellify/src/testutils/fixtures.ts
+++ b/client/codeintellify/src/testutils/fixtures.ts
@@ -2,7 +2,6 @@ import { of } from 'rxjs'
 import { delay } from 'rxjs/operators'
 
 import type { ActionsProvider, HoverProvider, DocumentHighlightProvider } from '../hoverifier'
-import type { MaybeLoadingResult } from '../loading'
 import type { HoverAttachment, DocumentHighlight } from '../types'
 
 /**
@@ -41,10 +40,7 @@ export function createStubHoverProvider(
     hover: Partial<HoverAttachment> = {},
     delayTime?: number
 ): HoverProvider<{}, {}> {
-    return () =>
-        of<MaybeLoadingResult<{}>>({ isLoading: false, result: createHoverAttachment(hover) }).pipe(
-            delay(delayTime ?? 0)
-        )
+    return () => of({ isLoading: false, result: createHoverAttachment(hover) }).pipe(delay(delayTime ?? 0))
 }
 
 /**
@@ -57,7 +53,7 @@ export function createStubDocumentHighlightProvider(
     documentHighlights: Partial<DocumentHighlight>[] = [],
     delayTime?: number
 ): DocumentHighlightProvider<{}> {
-    return () => of<DocumentHighlight[]>(documentHighlights.map(createDocumentHighlight)).pipe(delay(delayTime ?? 0))
+    return () => of(documentHighlights.map(createDocumentHighlight)).pipe(delay(delayTime ?? 0))
 }
 
 /**
diff --git a/client/common/BUILD.bazel b/client/common/BUILD.bazel
index 903146a63d2..a471484396e 100644
--- a/client/common/BUILD.bazel
+++ b/client/common/BUILD.bazel
@@ -46,6 +46,7 @@ ts_project(
         "src/util/path.ts",
         "src/util/rxjs/asObservable.ts",
         "src/util/rxjs/combineLatestOrDefault.ts",
+        "src/util/rxjs/fromSubscribable.ts",
         "src/util/rxjs/index.ts",
         "src/util/rxjs/memoizeObservable.ts",
         "src/util/rxjs/repeatUntil.ts",
@@ -71,6 +72,7 @@ ts_project(
         "//:node_modules/marked",
         "//:node_modules/react-router-dom",
         "//:node_modules/rxjs",
+        "//:node_modules/sourcegraph",
         "//:node_modules/utility-types",
     ],
 )
diff --git a/client/common/src/util/rxjs/combineLatestOrDefault.ts b/client/common/src/util/rxjs/combineLatestOrDefault.ts
index 389182d071b..5ed68f70f74 100644
--- a/client/common/src/util/rxjs/combineLatestOrDefault.ts
+++ b/client/common/src/util/rxjs/combineLatestOrDefault.ts
@@ -1,18 +1,4 @@
-/* eslint rxjs/no-internal: warn */
-import {
-    asapScheduler,
-    type ObservableInput,
-    of,
-    type Operator,
-    type PartialObserver,
-    type Subscriber,
-    type TeardownLogic,
-    zip,
-} from 'rxjs'
-import { Observable } from 'rxjs/internal/Observable'
-import { OuterSubscriber } from 'rxjs/internal/OuterSubscriber'
-import { subscribeToArray } from 'rxjs/internal/util/subscribeToArray'
-import { subscribeToResult } from 'rxjs/internal/util/subscribeToResult'
+import { asapScheduler, type ObservableInput, Observable, of, zip, from, Subscription } from 'rxjs'
 
 /**
  * Like {@link combineLatest}, except that it does not wait for all Observables to emit before emitting an initial
@@ -51,74 +37,68 @@ export function combineLatestOrDefault<T>(observables: ObservableInput<T>[], def
             return zip(...observables)
         }
         default: {
-            return new Observable<T[]>(subscribeToArray(observables)).lift(new CombineLatestOperator(defaultValue))
-        }
-    }
-}
+            return new Observable<T[]>(subscriber => {
+                // The array of the most recent values from each input Observable.
+                // If a source Observable has not yet emitted a value, it will be represented by the
+                // defaultValue (if provided) or not at all (if not provided).
+                const values: T[] = defaultValue !== undefined ? observables.map(() => defaultValue) : []
 
-class CombineLatestOperator<T> implements Operator<T, T[]> {
-    constructor(private defaultValue?: T) {}
+                // Whether the emission of the values array has been scheduled
+                let scheduled = false
+                let scheduledWork: Subscription | undefined
+                // The number of source Observables that have not yet completed
+                // (so that we know when to complete the output Observable)
+                let activeObservables = observables.length
 
-    public call(subscriber: Subscriber<T[]>, source: any): TeardownLogic {
-        return source.subscribe(new CombineLatestSubscriber(subscriber, this.defaultValue))
-    }
-}
+                // When everything is done, clean up the values array
+                subscriber.add(() => {
+                    values.length = 0
+                })
 
-class CombineLatestSubscriber<T> extends OuterSubscriber<T, T[]> {
-    private activeObservables = 0
-    private values: any[] = []
-    private observables: Observable<any>[] = []
-    private scheduled = false
-
-    constructor(observer: PartialObserver<T[]>, private defaultValue?: T) {
-        super(observer)
-    }
-
-    protected _next(observable: any): void {
-        if (this.defaultValue !== undefined) {
-            this.values.push(this.defaultValue)
-        }
-        this.observables.push(observable)
-    }
-
-    protected _complete(): void {
-        this.activeObservables = this.observables.length
-        for (let index = 0; index < this.observables.length; index++) {
-            this.add(subscribeToResult(this, this.observables[index], this.observables[index], index))
-        }
-    }
-
-    public notifyComplete(): void {
-        this.activeObservables--
-        if (this.activeObservables === 0 && this.destination.complete) {
-            this.destination.complete()
-        }
-    }
-
-    public notifyNext(_outerValue: T, innerValue: T[], outerIndex: number): void {
-        const values = this.values
-        values[outerIndex] = innerValue
-
-        if (this.activeObservables === 1) {
-            // Only 1 observable is active, so no need to buffer.
-            //
-            // This makes it possible to use RxJS's `of` in tests without specifying an explicit scheduler.
-            if (this.destination.next) {
-                this.destination.next(this.values.slice())
-            }
-            return
-        }
-
-        // Buffer all next values that are emitted at the same time into one emission.
-        //
-        // This makes tests (using expectObservable) easier to write.
-        if (!this.scheduled) {
-            this.scheduled = true
-            asapScheduler.schedule(() => {
-                if (this.scheduled && this.destination.next) {
-                    this.destination.next(this.values.slice())
+                // Subscribe to each source Observable. The index of the source Observable is used to
+                // keep track of the most recent value from that Observable in the values array.
+                for (let index = 0; index < observables.length; index++) {
+                    subscriber.add(
+                        from(observables[index]).subscribe({
+                            next: value => {
+                                values[index] = value
+                                if (activeObservables === 1) {
+                                    // If only one source Observable is active, emit the values array immediately
+                                    // Abort any scheduled emission
+                                    scheduledWork?.unsubscribe()
+                                    scheduled = false
+                                    subscriber.next(values.slice())
+                                } else if (!scheduled) {
+                                    scheduled = true
+                                    // Use asapScheduler to emit the values array, so that all
+                                    // next values that are emitted at the same time are emitted together.
+                                    // This makes tests (using expectObservable) easier to write.
+                                    scheduledWork = asapScheduler.schedule(() => {
+                                        if (!subscriber.closed) {
+                                            subscriber.next(values.slice())
+                                            scheduled = false
+                                            if (activeObservables === 0) {
+                                                subscriber.complete()
+                                            }
+                                        }
+                                    })
+                                }
+                            },
+                            error: error => subscriber.error(error),
+                            complete: () => {
+                                activeObservables--
+                                if (activeObservables === 0 && !scheduled) {
+                                    subscriber.complete()
+                                }
+                            },
+                        })
+                    )
+                }
+
+                // When everything is done, clean up the values array
+                return () => {
+                    values.length = 0
                 }
-                this.scheduled = false
             })
         }
     }
diff --git a/client/common/src/util/rxjs/fromSubscribable.ts b/client/common/src/util/rxjs/fromSubscribable.ts
new file mode 100644
index 00000000000..4e60bcb5c20
--- /dev/null
+++ b/client/common/src/util/rxjs/fromSubscribable.ts
@@ -0,0 +1,14 @@
+import { Observable, isObservable } from 'rxjs'
+import { type Subscribable } from 'sourcegraph'
+
+/**
+ * Converts a Sourcegraph {@link Subscribable} to an {@link Observable}.
+ */
+export function fromSubscribable<T>(value: Subscribable<T>): Observable<T> {
+    if (isObservable(value)) {
+        // type casting should be fine since we already know that
+        // value is at least a Subscribable<T>
+        return value as Observable<T>
+    }
+    return new Observable<T>(subscriber => value.subscribe(subscriber))
+}
diff --git a/client/common/src/util/rxjs/index.ts b/client/common/src/util/rxjs/index.ts
index 89f4fcd4754..e33b08dc252 100644
--- a/client/common/src/util/rxjs/index.ts
+++ b/client/common/src/util/rxjs/index.ts
@@ -2,3 +2,4 @@ export * from './asObservable'
 export * from './combineLatestOrDefault'
 export * from './memoizeObservable'
 export * from './repeatUntil'
+export * from './fromSubscribable'
diff --git a/client/jetbrains/webview/src/sourcegraph-api-access/api-gateway.ts b/client/jetbrains/webview/src/sourcegraph-api-access/api-gateway.ts
index 5c259992448..e6ffd245a0a 100644
--- a/client/jetbrains/webview/src/sourcegraph-api-access/api-gateway.ts
+++ b/client/jetbrains/webview/src/sourcegraph-api-access/api-gateway.ts
@@ -1,3 +1,5 @@
+import { lastValueFrom } from 'rxjs'
+
 import { gql, requestGraphQLCommon } from '@sourcegraph/http-client'
 import type { AuthenticatedUser } from '@sourcegraph/shared/src/auth'
 import type { CurrentAuthStateResult, CurrentAuthStateVariables } from '@sourcegraph/shared/src/graphql-operations'
@@ -57,18 +59,20 @@ export async function getSiteVersionAndAuthenticatedUser(
         return { site: null, currentUser: null }
     }
 
-    const result = await requestGraphQLCommon<SiteVersionAndCurrentAuthStateResult, CurrentAuthStateVariables>({
-        request: siteVersionAndUserQuery,
-        variables: {},
-        baseUrl: instanceURL,
-        headers: {
-            Accept: 'application/json',
-            'Content-Type': 'application/json',
-            'X-Sourcegraph-Should-Trace': new URLSearchParams(window.location.search).get('trace') || 'false',
-            ...(accessToken && { Authorization: `token ${accessToken}` }),
-            ...customRequestHeaders,
-        },
-    }).toPromise()
+    const result = await lastValueFrom(
+        requestGraphQLCommon<SiteVersionAndCurrentAuthStateResult, CurrentAuthStateVariables>({
+            request: siteVersionAndUserQuery,
+            variables: {},
+            baseUrl: instanceURL,
+            headers: {
+                Accept: 'application/json',
+                'Content-Type': 'application/json',
+                'X-Sourcegraph-Should-Trace': new URLSearchParams(window.location.search).get('trace') || 'false',
+                ...(accessToken && { Authorization: `token ${accessToken}` }),
+                ...customRequestHeaders,
+            },
+        })
+    )
 
     return result.data ?? { site: null, currentUser: null }
 }
diff --git a/client/shared/src/actions/ActionsNavItems.tsx b/client/shared/src/actions/ActionsNavItems.tsx
index b2873749903..f1a644e07a8 100644
--- a/client/shared/src/actions/ActionsNavItems.tsx
+++ b/client/shared/src/actions/ActionsNavItems.tsx
@@ -82,12 +82,12 @@ export interface ActionsNavItemsProps
 export const ActionsNavItems: React.FunctionComponent<React.PropsWithChildren<ActionsNavItemsProps>> = props => {
     const { scope, extraContext, extensionsController, menu, wrapInList, transformContributions = identity } = props
 
-    const scopeChanges = useMemo(() => new ReplaySubject<ContributionScope>(1), [])
+    const scopeChanges = useMemo(() => new ReplaySubject<ContributionScope | undefined>(1), [])
     useDeepCompareEffectNoCheck(() => {
         scopeChanges.next(scope)
     }, [scope])
 
-    const extraContextChanges = useMemo(() => new ReplaySubject<Context<unknown>>(1), [])
+    const extraContextChanges = useMemo(() => new ReplaySubject<Context<unknown> | undefined>(1), [])
     useDeepCompareEffectNoCheck(() => {
         extraContextChanges.next(extraContext)
     }, [extraContext])
diff --git a/client/shared/src/api/client/api/common.ts b/client/shared/src/api/client/api/common.ts
index 2564dfe516d..6a3b4c91997 100644
--- a/client/shared/src/api/client/api/common.ts
+++ b/client/shared/src/api/client/api/common.ts
@@ -1,6 +1,5 @@
 import { type Remote, proxyMarker, releaseProxy, type ProxyMethods, type ProxyOrClone } from 'comlink'
-import { noop } from 'lodash'
-import { from, type Observable, observable as symbolObservable, Subscription, type Subscribable } from 'rxjs'
+import { from, Observable, Subscription } from 'rxjs'
 import { mergeMap, finalize } from 'rxjs/operators'
 
 import { asError, logger } from '@sourcegraph/common'
@@ -59,37 +58,18 @@ export const wrapRemoteObservable = <T>(
     const observable = from(
         isPromiseLike(proxyOrProxyPromise) ? proxyOrProxyPromise : Promise.resolve(proxyOrProxyPromise)
     ).pipe(
-        mergeMap((proxySubscribable): Subscribable<ProxyOrClone<T>> => {
+        mergeMap((proxySubscribable): Observable<ProxyOrClone<T>> => {
             proxySubscription.add(new ProxySubscription(proxySubscribable))
-            return {
-                // Needed for Rx type check
-                [symbolObservable](): Subscribable<ProxyOrClone<T>> {
-                    return this
-                },
-                subscribe(...args: any[]): Subscription {
-                    // Always subscribe with an object because the other side
-                    // is unable to tell if a Proxy is a function or an observer object
-                    // (they always appear as functions)
-                    let proxyObserver: Parameters<typeof proxySubscribable['subscribe']>[0]
-                    if (typeof args[0] === 'function') {
-                        proxyObserver = {
-                            [proxyMarker]: true,
-                            next: args[0] || noop,
-                            error: args[1] ? error => args[1](asError(error)) : noop,
-                            complete: args[2] || noop,
-                        }
-                    } else {
-                        const partialObserver = args[0] || {}
-                        proxyObserver = {
-                            [proxyMarker]: true,
-                            next: partialObserver.next ? value => partialObserver.next(value) : noop,
-                            error: partialObserver.error ? error => partialObserver.error(asError(error)) : noop,
-                            complete: partialObserver.complete ? () => partialObserver.complete() : noop,
-                        }
-                    }
-                    return syncRemoteSubscription(proxySubscribable.subscribe(proxyObserver))
-                },
-            }
+            return new Observable(subscriber => {
+                const proxyObserver: Parameters<typeof proxySubscribable['subscribe']>[0] = {
+                    [proxyMarker]: true,
+                    // @ts-expect-error - this was previously typed as any
+                    next: value => subscriber.next(value),
+                    error: error => subscriber.error(asError(error)),
+                    complete: () => subscriber.complete(),
+                }
+                return syncRemoteSubscription(proxySubscribable.subscribe(proxyObserver))
+            })
         })
     )
     return Object.assign(observable, { proxySubscription })
diff --git a/client/shared/src/api/client/connection.ts b/client/shared/src/api/client/connection.ts
index c60c64edf03..cc119403a12 100644
--- a/client/shared/src/api/client/connection.ts
+++ b/client/shared/src/api/client/connection.ts
@@ -1,6 +1,5 @@
 import * as comlink from 'comlink'
-import { from, Subscription, type Unsubscribable } from 'rxjs'
-import { first } from 'rxjs/operators'
+import { firstValueFrom, Subscription, type Unsubscribable } from 'rxjs'
 
 import { logger } from '@sourcegraph/common'
 
@@ -42,7 +41,7 @@ export async function createExtensionHostClientConnection(
     /** Proxy to the exposed extension host API */
     const initializeExtensionHost = comlink.wrap<ExtensionHostAPIFactory>(endpoints.proxy)
 
-    const initialSettings = await from(platformContext.settings).pipe(first()).toPromise()
+    const initialSettings = await firstValueFrom(platformContext.settings)
     const proxy = await initializeExtensionHost({
         ...initData,
         // TODO what to do in error case?
diff --git a/client/shared/src/api/client/mainthread-api.test.ts b/client/shared/src/api/client/mainthread-api.test.ts
index 7eae423c44f..7d238751722 100644
--- a/client/shared/src/api/client/mainthread-api.test.ts
+++ b/client/shared/src/api/client/mainthread-api.test.ts
@@ -19,7 +19,7 @@ describe('MainThreadAPI', () => {
 
     describe('graphQL', () => {
         test('PlatformContext#requestGraphQL is called with the correct arguments', async () => {
-            const requestGraphQL = sinon.spy(_options => EMPTY)
+            const requestGraphQL = sinon.spy(_options => of({ data: null, errors: [] }))
 
             const platformContext: Pick<
                 PlatformContext,
diff --git a/client/shared/src/api/client/mainthread-api.ts b/client/shared/src/api/client/mainthread-api.ts
index 5b7e08a84f6..7b22c17a87e 100644
--- a/client/shared/src/api/client/mainthread-api.ts
+++ b/client/shared/src/api/client/mainthread-api.ts
@@ -1,5 +1,5 @@
 import { type Remote, proxy } from 'comlink'
-import { type Unsubscribable, Subscription, from, of } from 'rxjs'
+import { type Unsubscribable, Subscription, from, of, lastValueFrom } from 'rxjs'
 import { publishReplay, refCount, switchMap } from 'rxjs/operators'
 
 import { logger } from '@sourcegraph/common'
@@ -101,13 +101,13 @@ export const initMainThreadAPI = (
     const api: MainThreadAPI = {
         applySettingsEdit: edit => updateSettings(platformContext, edit),
         requestGraphQL: (request, variables) =>
-            platformContext
-                .requestGraphQL({
+            lastValueFrom(
+                platformContext.requestGraphQL({
                     request,
                     variables,
                     mightContainPrivateInfo: true,
                 })
-                .toPromise(),
+            ),
         // Commands
         executeCommand: (command, args) => executeCommand({ command, args }),
         registerCommand: (command, run) => {
diff --git a/client/shared/src/api/client/services/settings.ts b/client/shared/src/api/client/services/settings.ts
index b56a7c3803f..a252915cb06 100644
--- a/client/shared/src/api/client/services/settings.ts
+++ b/client/shared/src/api/client/services/settings.ts
@@ -1,5 +1,4 @@
-import { from } from 'rxjs'
-import { first } from 'rxjs/operators'
+import { firstValueFrom } from 'rxjs'
 
 import type { KeyPath } from '@sourcegraph/client-api'
 
@@ -28,7 +27,7 @@ export async function updateSettings(
     edit: SettingsEdit
 ): Promise<void> {
     const { settings: data, updateSettings: update } = platformContext
-    const settings = await from(data).pipe(first()).toPromise()
+    const settings = await firstValueFrom(data)
     if (!isSettingsValid(settings)) {
         throw new Error('invalid settings (internal error)')
     }
diff --git a/client/shared/src/api/contract.ts b/client/shared/src/api/contract.ts
index ef825b50f2a..e5d7ad1d668 100644
--- a/client/shared/src/api/contract.ts
+++ b/client/shared/src/api/contract.ts
@@ -1,6 +1,5 @@
 import type { Remote, ProxyMarked } from 'comlink'
 import type { Unsubscribable } from 'rxjs'
-import type { DocumentHighlight } from 'sourcegraph'
 
 import type {
     Contributions,
@@ -13,7 +12,7 @@ import type { MaybeLoadingResult } from '@sourcegraph/codeintellify'
 import type * as clientType from '@sourcegraph/extension-api-types'
 import type { GraphQLResult } from '@sourcegraph/http-client'
 
-import type { ReferenceContext } from '../codeintel/legacy-extensions/api'
+import type { DocumentHighlight, ReferenceContext } from '../codeintel/legacy-extensions/api'
 import type { Occurrence } from '../codeintel/scip'
 import type { ConfiguredExtension } from '../extensions/extension'
 import type { SettingsCascade } from '../settings/settings'
diff --git a/client/shared/src/api/extension/api/common.ts b/client/shared/src/api/extension/api/common.ts
index 6f4c86a04e7..3518d5bdd35 100644
--- a/client/shared/src/api/extension/api/common.ts
+++ b/client/shared/src/api/extension/api/common.ts
@@ -1,8 +1,10 @@
 import { type Remote, type ProxyMarked, proxy, proxyMarker, type UnproxyOrClone } from 'comlink'
 import { identity } from 'lodash'
-import { from, isObservable, type Observable, type Observer, of, type Subscribable, type Unsubscribable } from 'rxjs'
+import { from, isObservable, type Observable, type Observer, of, type Unsubscribable, ObservableInput } from 'rxjs'
 import { map } from 'rxjs/operators'
-import type { ProviderResult } from 'sourcegraph'
+import type { ProviderResult, Subscribable } from 'sourcegraph'
+
+import { fromSubscribable } from '@sourcegraph/common'
 
 import { isAsyncIterable, isPromiseLike, isSubscribable, observableFromAsyncIterable } from '../../util'
 
@@ -50,8 +52,10 @@ export function providerResultToObservable<T, R = T>(
     mapFunc: (value: T | undefined | null) => R = identity
 ): Observable<R> {
     let observable: Observable<R>
-    if (result && (isPromiseLike(result) || isObservable<T>(result) || isSubscribable(result))) {
-        observable = from(result).pipe(map(mapFunc))
+    if (result && (isPromiseLike(result) || isObservable(result))) {
+        observable = from(result as ObservableInput<T>).pipe(map(mapFunc))
+    } else if (isSubscribable(result)) {
+        observable = fromSubscribable(result as Subscribable<T>).pipe(map(mapFunc))
     } else if (isAsyncIterable(result)) {
         observable = observableFromAsyncIterable(result).pipe(map(mapFunc))
     } else {
diff --git a/client/shared/src/api/extension/extensionHostApi.ts b/client/shared/src/api/extension/extensionHostApi.ts
index a0cde462607..6416b91cf08 100644
--- a/client/shared/src/api/extension/extensionHostApi.ts
+++ b/client/shared/src/api/extension/extensionHostApi.ts
@@ -1,6 +1,6 @@
 import { proxy } from 'comlink'
 import { castArray, isEqual } from 'lodash'
-import { combineLatest, concat, type Observable, of, type Subscribable } from 'rxjs'
+import { combineLatest, concat, type Observable, of } from 'rxjs'
 import { catchError, defaultIfEmpty, distinctUntilChanged, map, switchMap } from 'rxjs/operators'
 import type { ProviderResult } from 'sourcegraph'
 
@@ -319,7 +319,7 @@ export function createExtensionHostAPI(state: ExtensionHostState): FlatExtension
                         })
                     ),
                     state.settings,
-                    state.context as Subscribable<Context<unknown>>,
+                    state.context as Observable<Context<unknown>>,
                 ]).pipe(
                     map(([multiContributions, activeEditor, settings, context]) => {
                         // Merge in extra context.
@@ -431,7 +431,7 @@ export function callProviders<TRegisteredProvider, TProviderResult, TMergedResul
                         concat(
                             [LOADING],
                             providerResultToObservable(safeInvokeProvider(provider)).pipe(
-                                defaultIfEmpty<typeof LOADING | TProviderResult | null | undefined>(null),
+                                defaultIfEmpty(null),
                                 catchError(error => {
                                     logError(error)
                                     return [null]
@@ -443,7 +443,7 @@ export function callProviders<TRegisteredProvider, TProviderResult, TMergedResul
             )
         )
         .pipe(
-            defaultIfEmpty<(typeof LOADING | TProviderResult | null | undefined)[]>([]),
+            defaultIfEmpty([]),
             map(results => ({
                 isLoading: results.some(hover => hover === LOADING),
                 result: mergeResult(results),
diff --git a/client/shared/src/api/extension/test/extensionHost.documentHighlights.test.ts b/client/shared/src/api/extension/test/extensionHost.documentHighlights.test.ts
index fe722decf79..c63f3e79805 100644
--- a/client/shared/src/api/extension/test/extensionHost.documentHighlights.test.ts
+++ b/client/shared/src/api/extension/test/extensionHost.documentHighlights.test.ts
@@ -61,6 +61,7 @@ describe('getDocumentHighlights from ExtensionHost API, it aims to have more e2e
                 position: { line: 1, character: 2 },
                 textDocument: { uri: typescriptFileUri },
             })
+            // @ts-expect-error - Unclear how to consolidate the different versions of the DocumentHighlight types
             .subscribe(observe(value => results.push(value)))
 
         // first provider results
diff --git a/client/shared/src/api/integration-test/codeEditor.test.ts b/client/shared/src/api/integration-test/codeEditor.test.ts
index 98837f570a2..19a16515ec4 100644
--- a/client/shared/src/api/integration-test/codeEditor.test.ts
+++ b/client/shared/src/api/integration-test/codeEditor.test.ts
@@ -1,7 +1,8 @@
-import { from } from 'rxjs'
+import { lastValueFrom } from 'rxjs'
 import { distinctUntilChanged, switchMap, take, toArray } from 'rxjs/operators'
 import { describe, test } from 'vitest'
 
+import { fromSubscribable } from '@sourcegraph/common'
 import { Selection } from '@sourcegraph/extension-api-classes'
 
 import { assertToJSON, integrationTestContext } from '../../testing/testHelpers'
@@ -11,14 +12,16 @@ describe('CodeEditor (integration)', () => {
         test('observe changes', async () => {
             const { extensionAPI, extensionHostAPI } = await integrationTestContext()
 
-            const values = from(extensionAPI.app.activeWindow!.activeViewComponentChanges)
-                .pipe(
-                    switchMap(viewer => (viewer && viewer.type === 'CodeEditor' ? viewer.selectionsChanges : [])),
+            const values = lastValueFrom(
+                fromSubscribable(extensionAPI.app.activeWindow!.activeViewComponentChanges).pipe(
+                    switchMap(viewer =>
+                        viewer && viewer.type === 'CodeEditor' ? fromSubscribable(viewer.selectionsChanges) : []
+                    ),
                     distinctUntilChanged(),
                     take(3),
                     toArray()
                 )
-                .toPromise()
+            )
 
             await extensionHostAPI.setEditorSelections({ viewerId: 'viewer#0' }, [new Selection(1, 2, 3, 4)])
             await extensionHostAPI.setEditorSelections({ viewerId: 'viewer#0' }, [])
diff --git a/client/shared/src/api/integration-test/documents.test.ts b/client/shared/src/api/integration-test/documents.test.ts
index 5d5861a938e..c872cc4dbde 100644
--- a/client/shared/src/api/integration-test/documents.test.ts
+++ b/client/shared/src/api/integration-test/documents.test.ts
@@ -1,5 +1,7 @@
 import { describe, expect, test } from 'vitest'
 
+import { fromSubscribable } from '@sourcegraph/common'
+
 import type { TextDocument } from '../../codeintel/legacy-extensions/api'
 import { assertToJSON, collectSubscribableValues, integrationTestContext } from '../../testing/testHelpers'
 
@@ -28,7 +30,7 @@ describe('Documents (integration)', () => {
         test('fires when a text document is opened', async () => {
             const { extensionAPI, extensionHostAPI } = await integrationTestContext()
 
-            const values = collectSubscribableValues(extensionAPI.workspace.openedTextDocuments)
+            const values = collectSubscribableValues(fromSubscribable(extensionAPI.workspace.openedTextDocuments))
             expect(values).toEqual([] as TextDocument[])
 
             await extensionHostAPI.addTextDocumentIfNotExists({ uri: 'file:///f2', languageId: 'l2', text: 't2' })
diff --git a/client/shared/src/api/integration-test/roots.test.ts b/client/shared/src/api/integration-test/roots.test.ts
index b27259a4b96..f968014d375 100644
--- a/client/shared/src/api/integration-test/roots.test.ts
+++ b/client/shared/src/api/integration-test/roots.test.ts
@@ -1,5 +1,7 @@
 import { describe, expect, test } from 'vitest'
 
+import { fromSubscribable } from '@sourcegraph/common'
+
 import type { WorkspaceRoot } from '../../codeintel/legacy-extensions/api'
 import { collectSubscribableValues, integrationTestContext } from '../../testing/testHelpers'
 
@@ -34,7 +36,7 @@ describe('Workspace roots (integration)', () => {
         test('fires when a root is added or removed', async () => {
             const { extensionAPI, extensionHostAPI } = await integrationTestContext()
 
-            const values = collectSubscribableValues(extensionAPI.workspace.rootChanges)
+            const values = collectSubscribableValues(fromSubscribable(extensionAPI.workspace.rootChanges))
             expect(values).toEqual([] as void[])
 
             await extensionHostAPI.addWorkspaceRoot({
diff --git a/client/shared/src/api/integration-test/selections.test.ts b/client/shared/src/api/integration-test/selections.test.ts
index 42f99142fe1..33d23ac0c44 100644
--- a/client/shared/src/api/integration-test/selections.test.ts
+++ b/client/shared/src/api/integration-test/selections.test.ts
@@ -1,8 +1,7 @@
-import { from } from 'rxjs'
 import { distinctUntilChanged, filter, switchMap } from 'rxjs/operators'
 import { describe, test } from 'vitest'
 
-import { isDefined, isTaggedUnionMember } from '@sourcegraph/common'
+import { fromSubscribable, isDefined, isTaggedUnionMember } from '@sourcegraph/common'
 
 import { assertToJSON, collectSubscribableValues, integrationTestContext } from '../../testing/testHelpers'
 
@@ -10,13 +9,13 @@ describe('Selections (integration)', () => {
     describe('editor.selectionsChanged', () => {
         test('reflects changes to the current selections', async () => {
             const { extensionAPI, extensionHostAPI } = await integrationTestContext()
-            const selectionChanges = from(extensionAPI.app.activeWindowChanges).pipe(
+            const selectionChanges = fromSubscribable(extensionAPI.app.activeWindowChanges).pipe(
                 filter(isDefined),
-                switchMap(window => window.activeViewComponentChanges),
+                switchMap(window => fromSubscribable(window.activeViewComponentChanges)),
                 filter(isDefined),
                 filter(isTaggedUnionMember('type', 'CodeEditor' as const)),
                 distinctUntilChanged(),
-                switchMap(editor => editor.selectionsChanges)
+                switchMap(editor => fromSubscribable(editor.selectionsChanges))
             )
             const selectionValues = collectSubscribableValues(selectionChanges)
             const testValues = [
diff --git a/client/shared/src/api/integration-test/windows.test.ts b/client/shared/src/api/integration-test/windows.test.ts
index d3d35e117c5..10d702aadae 100644
--- a/client/shared/src/api/integration-test/windows.test.ts
+++ b/client/shared/src/api/integration-test/windows.test.ts
@@ -1,9 +1,11 @@
 import { pick } from 'lodash'
-import { from, of } from 'rxjs'
+import { lastValueFrom, of } from 'rxjs'
 import { switchMap, take, toArray } from 'rxjs/operators'
 import type { ViewComponent, Window } from 'sourcegraph'
 import { describe, expect, test } from 'vitest'
 
+import { fromSubscribable } from '@sourcegraph/common'
+
 import { assertToJSON, integrationTestContext } from '../../testing/testHelpers'
 import type { TextDocumentData } from '../viewerTypes'
 
@@ -159,13 +161,15 @@ describe('Windows (integration)', () => {
                     viewers: [],
                 })
 
-                const viewers = from(extensionAPI.app.activeWindowChanges)
-                    .pipe(
-                        switchMap(activeWindow => (activeWindow ? activeWindow.activeViewComponentChanges : of(null))),
+                const viewers = lastValueFrom(
+                    fromSubscribable(extensionAPI.app.activeWindowChanges).pipe(
+                        switchMap(activeWindow =>
+                            activeWindow ? fromSubscribable(activeWindow.activeViewComponentChanges) : of(null)
+                        ),
                         take(4),
                         toArray()
                     )
-                    .toPromise()
+                )
 
                 await extensionHostAPI.addTextDocumentIfNotExists({ uri: 'foo', languageId: 'l1', text: 't1' })
                 await extensionHostAPI.addTextDocumentIfNotExists({ uri: 'bar', languageId: 'l2', text: 't2' })
diff --git a/client/shared/src/api/util.ts b/client/shared/src/api/util.ts
index 8689fbf3c15..8d06e0ce5e9 100644
--- a/client/shared/src/api/util.ts
+++ b/client/shared/src/api/util.ts
@@ -6,14 +6,8 @@ import {
     type Remote,
     proxyMarker,
 } from 'comlink'
-import {
-    type Unsubscribable,
-    type Subscribable,
-    Observable,
-    type Observer,
-    type PartialObserver,
-    Subscription,
-} from 'rxjs'
+import { type Unsubscribable, Observable, type Observer, type PartialObserver, Subscription } from 'rxjs'
+import { Subscribable } from 'sourcegraph'
 
 import { hasProperty, AbortError } from '@sourcegraph/common'
 
diff --git a/client/shared/src/codeintel/api.ts b/client/shared/src/codeintel/api.ts
index 1d67dbe9ae2..ac80f7bd757 100644
--- a/client/shared/src/codeintel/api.ts
+++ b/client/shared/src/codeintel/api.ts
@@ -1,5 +1,5 @@
 import { castArray } from 'lodash'
-import { from, type Observable, of } from 'rxjs'
+import { from, of, lastValueFrom } from 'rxjs'
 import { defaultIfEmpty, map } from 'rxjs/operators'
 
 import {
@@ -42,7 +42,7 @@ export interface CodeIntelAPI {
         scipParameters?: ScipParameters
     ): Promise<clientType.Location[]>
     getImplementations(parameters: TextDocumentPositionParameters): Promise<clientType.Location[]>
-    getHover(textParameters: TextDocumentPositionParameters): Promise<HoverMerged | null | undefined>
+    getHover(textParameters: TextDocumentPositionParameters): Promise<HoverMerged | null>
     getDocumentHighlights(textParameters: TextDocumentPositionParameters): Promise<DocumentHighlight[]>
 }
 
@@ -57,9 +57,9 @@ export async function getOrCreateCodeIntelAPI(context: PlatformContext): Promise
         return codeIntelAPI
     }
 
-    return new Promise<CodeIntelAPI>((resolve, reject) => {
-        context.settings.subscribe(settingsCascade => {
-            try {
+    return lastValueFrom(
+        context.settings.pipe(
+            map(settingsCascade => {
                 if (!isSettingsValid(settingsCascade)) {
                     throw new Error('Settings are not valid')
                 }
@@ -68,28 +68,27 @@ export async function getOrCreateCodeIntelAPI(context: PlatformContext): Promise
                     telemetryService: context.telemetryService,
                     settings: newSettingsGetter(settingsCascade),
                 })
-                resolve(codeIntelAPI)
-            } catch (error) {
-                reject(error)
-            }
-        })
-    })
+                return codeIntelAPI
+            })
+        )
+    )
 }
 
 class DefaultCodeIntelAPI implements CodeIntelAPI {
     private locationResult(
         locations: sourcegraph.ProviderResult<sourcegraph.Definition>
     ): Promise<clientType.Location[]> {
-        return locations
-            .pipe(
-                defaultIfEmpty(),
+        return lastValueFrom(
+            locations.pipe(
+                defaultIfEmpty(undefined),
                 map(result =>
                     castArray(result)
                         .filter(isDefined)
                         .map(location => ({ ...location, uri: location.uri.toString() }))
                 )
-            )
-            .toPromise()
+            ),
+            { defaultValue: [] }
+        )
     }
 
     public hasReferenceProvidersForDocument(textParameters: TextDocumentPositionParameters): Promise<boolean> {
@@ -128,26 +127,26 @@ class DefaultCodeIntelAPI implements CodeIntelAPI {
             request.providers.implementations.provideLocations(request.document, request.position)
         )
     }
-    public getHover(textParameters: TextDocumentPositionParameters): Promise<HoverMerged | null | undefined> {
+    public getHover(textParameters: TextDocumentPositionParameters): Promise<HoverMerged | null> {
         const request = requestFor(textParameters)
-        return (
+        return lastValueFrom(
             request.providers.hover
                 .provideHover(request.document, request.position)
                 // We intentionally don't use `defaultIfEmpty()` here because
                 // that makes the popover load with an empty docstring.
-                .pipe(map(result => fromHoverMerged([result])))
-                .toPromise()
+                .pipe(map(result => fromHoverMerged([result]))),
+            { defaultValue: null }
         )
     }
     public getDocumentHighlights(textParameters: TextDocumentPositionParameters): Promise<DocumentHighlight[]> {
         const request = requestFor(textParameters)
-        return request.providers.documentHighlights
-            .provideDocumentHighlights(request.document, request.position)
-            .pipe(
-                defaultIfEmpty(),
+        return lastValueFrom(
+            request.providers.documentHighlights.provideDocumentHighlights(request.document, request.position).pipe(
+                defaultIfEmpty(undefined),
                 map(result => result || [])
-            )
-            .toPromise()
+            ),
+            { defaultValue: [] }
+        )
     }
 }
 
@@ -242,13 +241,8 @@ export function injectNewCodeintel(
 }
 
 export function newCodeIntelExtensionHostAPI(codeintel: CodeIntelAPI): CodeIntelExtensionHostAPI {
-    function thenMaybeLoadingResult<T>(promise: Observable<T>): Observable<MaybeLoadingResult<T>> {
-        return promise.pipe(
-            map(result => {
-                const maybeLoadingResult: MaybeLoadingResult<T> = { isLoading: false, result }
-                return maybeLoadingResult
-            })
-        )
+    function thenMaybeLoadingResult<T>(result: T): MaybeLoadingResult<T> {
+        return { isLoading: false, result }
     }
 
     return {
@@ -257,22 +251,22 @@ export function newCodeIntelExtensionHostAPI(codeintel: CodeIntelAPI): CodeIntel
         },
         getLocations(id, parameters) {
             if (!id.startsWith('implementations_')) {
-                return proxySubscribable(thenMaybeLoadingResult(of([])))
+                return proxySubscribable(of({ isLoading: false, result: [] }))
             }
-            return proxySubscribable(thenMaybeLoadingResult(from(codeintel.getImplementations(parameters))))
+            return proxySubscribable(from(codeintel.getImplementations(parameters).then(thenMaybeLoadingResult)))
         },
         getDefinition(parameters) {
-            return proxySubscribable(thenMaybeLoadingResult(from(codeintel.getDefinition(parameters))))
+            return proxySubscribable(from(codeintel.getDefinition(parameters).then(thenMaybeLoadingResult)))
         },
         getReferences(parameters, context, scipParameters) {
             return proxySubscribable(
-                thenMaybeLoadingResult(from(codeintel.getReferences(parameters, context, scipParameters)))
+                from(codeintel.getReferences(parameters, context, scipParameters).then(thenMaybeLoadingResult))
             )
         },
         getDocumentHighlights: (textParameters: TextDocumentPositionParameters) =>
             proxySubscribable(from(codeintel.getDocumentHighlights(textParameters))),
         getHover: (textParameters: TextDocumentPositionParameters) =>
-            proxySubscribable(thenMaybeLoadingResult(from(codeintel.getHover(textParameters)))),
+            proxySubscribable(from(codeintel.getHover(textParameters).then(thenMaybeLoadingResult))),
     }
 }
 
diff --git a/client/shared/src/codeintel/legacy-extensions/api.ts b/client/shared/src/codeintel/legacy-extensions/api.ts
index 32b98d6ee6b..04ea5b2266c 100644
--- a/client/shared/src/codeintel/legacy-extensions/api.ts
+++ b/client/shared/src/codeintel/legacy-extensions/api.ts
@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-import type { Observable, Unsubscribable } from 'rxjs'
+import { lastValueFrom, type Observable, type Unsubscribable } from 'rxjs'
 
 import type { GraphQLResult } from '@sourcegraph/http-client'
 
@@ -361,10 +361,9 @@ export function requestGraphQL<T>(query: string, vars?: { [name: string]: unknow
             )
         )
     }
-    return context
-
-        .requestGraphQL<T, any>({ request: query, variables: vars as any, mightContainPrivateInfo: true })
-        .toPromise()
+    return lastValueFrom(
+        context.requestGraphQL<T, any>({ request: query, variables: vars as any, mightContainPrivateInfo: true })
+    )
 }
 
 export function getSetting<T>(key: string): T | undefined {
diff --git a/client/shared/src/hover/actions.test.ts b/client/shared/src/hover/actions.test.ts
index 35e88eab42b..74973a39701 100644
--- a/client/shared/src/hover/actions.test.ts
+++ b/client/shared/src/hover/actions.test.ts
@@ -396,7 +396,7 @@ describe('getDefinitionURL', () => {
                         Partial<ViewStateSpec>
                 ) => ''
             )
-            await of<MaybeLoadingResult<Location[]>>({
+            await of({
                 isLoading: false,
                 result: [{ uri: 'git://r3?c3#f' }],
             })
@@ -424,7 +424,7 @@ describe('getDefinitionURL', () => {
         describe('when the result is inside the current root', () => {
             it('emits the definition URL the user input revision (not commit SHA) of the root', () =>
                 expect(
-                    of<MaybeLoadingResult<Location[]>>({
+                    of({
                         isLoading: false,
                         result: [{ uri: 'git://r3?c3#f' }],
                     })
@@ -445,7 +445,7 @@ describe('getDefinitionURL', () => {
         describe('when the result is not inside the current root (different repo and/or commit)', () => {
             it('emits the definition URL with range', () =>
                 expect(
-                    of<MaybeLoadingResult<Location[]>>({
+                    of({
                         isLoading: false,
                         result: [FIXTURE_LOCATION_CLIENT],
                     })
@@ -464,7 +464,7 @@ describe('getDefinitionURL', () => {
 
             it('emits the definition URL without range', () =>
                 expect(
-                    of<MaybeLoadingResult<Location[]>>({
+                    of({
                         isLoading: false,
                         result: [{ ...FIXTURE_LOCATION_CLIENT, range: undefined }],
                     })
@@ -485,7 +485,7 @@ describe('getDefinitionURL', () => {
 
     it('emits the definition panel URL if there is more than 1 location result', () =>
         expect(
-            of<MaybeLoadingResult<Location[]>>({
+            of({
                 isLoading: false,
                 result: [FIXTURE_LOCATION_CLIENT, { ...FIXTURE_LOCATION, uri: 'other' }],
             })
diff --git a/client/shared/src/hover/actions.ts b/client/shared/src/hover/actions.ts
index 0ac00e3f780..04f00cac531 100644
--- a/client/shared/src/hover/actions.ts
+++ b/client/shared/src/hover/actions.ts
@@ -1,7 +1,18 @@
 import type { Remote } from 'comlink'
 import * as H from 'history'
 import { isEqual, uniqWith } from 'lodash'
-import { combineLatest, merge, type Observable, of, Subscription, type Unsubscribable, concat, from, EMPTY } from 'rxjs'
+import {
+    combineLatest,
+    merge,
+    type Observable,
+    of,
+    Subscription,
+    type Unsubscribable,
+    concat,
+    from,
+    EMPTY,
+    lastValueFrom,
+} from 'rxjs'
 import {
     catchError,
     delay,
@@ -246,7 +257,7 @@ export const getDefinitionURL =
                     Partial<MaybeLoadingResult<UIDefinitionURL | null>>
                 > => {
                     if (definitions.length === 0) {
-                        return of<MaybeLoadingResult<UIDefinitionURL | null>>({ isLoading, result: null })
+                        return of({ isLoading, result: null })
                     }
 
                     // Get unique definitions.
@@ -258,7 +269,7 @@ export const getDefinitionURL =
                             workspaceRoots || [],
                             parseRepoURI(parameters.textDocument.uri)
                         )
-                        return of<MaybeLoadingResult<UIDefinitionURL | null>>({
+                        return of({
                             isLoading,
                             result: {
                                 url: urlToFile(
@@ -409,8 +420,8 @@ export function registerHoverContributions({
                         const parameters: TextDocumentPositionParameters & URLToFileContext =
                             JSON.parse(parametersString)
 
-                        const { result } = await wrapRemoteObservable(extensionHostAPI.getDefinition(parameters))
-                            .pipe(
+                        const { result } = await lastValueFrom(
+                            wrapRemoteObservable(extensionHostAPI.getDefinition(parameters)).pipe(
                                 getDefinitionURL(
                                     { urlToFile, requestGraphQL },
                                     {
@@ -425,7 +436,7 @@ export function registerHoverContributions({
                                 ),
                                 first(({ isLoading, result }) => !isLoading || result !== null)
                             )
-                            .toPromise()
+                        )
 
                         if (!result) {
                             throw new Error('No definition found.')
diff --git a/client/shared/src/platform/context.ts b/client/shared/src/platform/context.ts
index 4d88ec3f2f3..2cd929ebb54 100644
--- a/client/shared/src/platform/context.ts
+++ b/client/shared/src/platform/context.ts
@@ -1,6 +1,6 @@
 import type { Endpoint } from 'comlink'
 import { isObject } from 'lodash'
-import type { Observable, Subscribable, Subscription } from 'rxjs'
+import type { Observable, Subscription } from 'rxjs'
 
 import type { DiffPart } from '@sourcegraph/codeintellify'
 import { hasProperty } from '@sourcegraph/common'
@@ -73,7 +73,7 @@ export interface PlatformContext {
      *
      * @deprecated Use useSettings instead
      */
-    readonly settings: Subscribable<SettingsCascadeOrError<Settings>>
+    readonly settings: Observable<SettingsCascadeOrError<Settings>>
 
     /**
      * Update the settings for the subject, either by inserting/changing a specific value or by overwriting the
diff --git a/client/shared/src/testing/integration/context.ts b/client/shared/src/testing/integration/context.ts
index a4921064047..ff8e46a74a5 100644
--- a/client/shared/src/testing/integration/context.ts
+++ b/client/shared/src/testing/integration/context.ts
@@ -10,7 +10,7 @@ import type { Test } from 'mocha'
 import { readFile, mkdir } from 'mz/fs'
 import pTimeout from 'p-timeout'
 import * as prettier from 'prettier'
-import { Subject, Subscription, throwError } from 'rxjs'
+import { Subject, Subscription, lastValueFrom, throwError } from 'rxjs'
 import { first, timeoutWith } from 'rxjs/operators'
 
 import { STATIC_ASSETS_PATH } from '@sourcegraph/build-config'
@@ -288,15 +288,15 @@ export const createSharedIntegrationTestContext = async <
             triggerRequest: () => Promise<void> | void,
             operationName: O
         ): Promise<Parameters<TGraphQlOperations[O]>[0]> => {
-            const requestPromise = graphQlRequests
-                .pipe(
+            const requestPromise = lastValueFrom(
+                graphQlRequests.pipe(
                     first(
                         (request: GraphQLRequestEvent<TGraphQlOperationNames>): request is GraphQLRequestEvent<O> =>
                             request.operationName === operationName
                     ),
                     timeoutWith(4000, throwError(new Error(`Timeout waiting for GraphQL request "${operationName}"`)))
                 )
-                .toPromise()
+            )
             await triggerRequest()
             const { variables } = await requestPromise
             return variables
diff --git a/client/shared/src/testing/testHelpers.ts b/client/shared/src/testing/testHelpers.ts
index efe5424c8d6..ec105ad1b15 100644
--- a/client/shared/src/testing/testHelpers.ts
+++ b/client/shared/src/testing/testHelpers.ts
@@ -1,5 +1,5 @@
 import type { Remote } from 'comlink'
-import { throwError, of, Subscription, type Unsubscribable, type Subscribable } from 'rxjs'
+import { throwError, of, Subscription, type Unsubscribable, type Observable } from 'rxjs'
 import type * as sourcegraph from 'sourcegraph'
 import { expect } from 'vitest'
 
@@ -107,8 +107,9 @@ export async function integrationTestContext(
     }
 }
 
-export function collectSubscribableValues<T>(subscribable: Subscribable<T>): T[] {
+export function collectSubscribableValues<T>(observable: Observable<T>): T[] {
     const values: T[] = []
-    subscribable.subscribe(value => values.push(value))
+    // eslint-disable-next-line rxjs/no-ignored-subscription
+    observable.subscribe(value => values.push(value))
     return values
 }
diff --git a/client/shared/src/util/useInputValidation.ts b/client/shared/src/util/useInputValidation.ts
index 00445169762..46cdb3e27c7 100644
--- a/client/shared/src/util/useInputValidation.ts
+++ b/client/shared/src/util/useInputValidation.ts
@@ -180,7 +180,7 @@ export function createValidationPipeline(
         combineLatest([
             // Validate immediately if the user has provided an initial input value
             concat(
-                initialValue !== undefined ? of<InputValidationEvent>({ value: initialValue, validate: true }) : EMPTY,
+                initialValue !== undefined ? of({ value: initialValue, validate: true }) : EMPTY,
                 inputValidationEvents
             ),
             inputReferences,
diff --git a/client/web-sveltekit/src/lib/graphql/urql.ts b/client/web-sveltekit/src/lib/graphql/urql.ts
index 78842e6d5bb..5c29cf85ee7 100644
--- a/client/web-sveltekit/src/lib/graphql/urql.ts
+++ b/client/web-sveltekit/src/lib/graphql/urql.ts
@@ -206,7 +206,7 @@ export function infinityQuery<TData = any, TVariables extends AnyVariables = Any
                                 'query',
                                 createRequest(args.query, { ...initialVariables, ...variables })
                             )
-                            return concat<Partial<OperationResultState<TData, TVariables>>>(
+                            return concat(
                                 of({ fetching: true, stale: false, restoring: false }),
                                 from(args.client.executeRequestOperation(operation).toPromise()).pipe(
                                     map(({ data, stale, operation, error, extensions }) => ({
diff --git a/client/web-sveltekit/vite.config.ts b/client/web-sveltekit/vite.config.ts
index 32c657b941a..895a668fe29 100644
--- a/client/web-sveltekit/vite.config.ts
+++ b/client/web-sveltekit/vite.config.ts
@@ -73,33 +73,6 @@ export default defineConfig(({ mode }) => {
                     find: /^(.*)\.gql$/,
                     replacement: '$1.gql.ts',
                 },
-                // In rxjs v6 these are directories and cannot be imported from directly in the production build.
-                // The following error occurs:
-                // Error [ERR_UNSUPPORTED_DIR_IMPORT]: Directory import '[...]/node_modules/rxjs/operators' is not supported resolving ES modules
-                {
-                    find: /^rxjs\/(operators|fetch)$/,
-                    replacement: 'rxjs/$1/index.js',
-                    customResolver(source, importer, options) {
-                        // This is an hacky way to make the dev build work. @sourcegraph/telemetry uses a newer
-                        // version of rxjs (v7) where `rjx/operators` and `rxjs/fetch` are properly mapped
-                        // to their respective files in package.json.
-                        // Applying the same replacement to this version results in an error.
-                        // I tried various ways to prevent having the alias be applied to `@sourcegraph/telemetry`
-                        // without success:
-                        // - Removing this alias causes the production build to fail do the issue mentioned at the
-                        //   top of this alias.
-                        // - Adding something like `{ ssr: { external: '@sourcegraph/telemetry' } }` to the config
-                        //   does not prevent the alias from being applied. Maybe I don't understand how `external`
-                        //   is supposed to work.
-                        // - Using a custom plugin that implements a custom resolveId function is somehow not being
-                        //   run in the production build for `rxjs` imports. Maybe it has something to do with the
-                        //   interop between vite and sveltekit.
-                        if (importer?.includes('@sourcegraph/telemetry')) {
-                            source = source.replace('/index.js', '')
-                        }
-                        return this.resolve(source, importer, options)
-                    },
-                },
                 // Without aliasing lodash to lodash-es we get the following error:
                 // SyntaxError: Named export 'castArray' not found. The requested module 'lodash' is a CommonJS module, which may not support all module.exports as named exports.
                 {
diff --git a/client/web/dev/BUILD.bazel b/client/web/dev/BUILD.bazel
index e4717929267..6629934ea84 100644
--- a/client/web/dev/BUILD.bazel
+++ b/client/web/dev/BUILD.bazel
@@ -89,10 +89,6 @@ esbuild(
         "path-browserify",
         "monaco-yaml/lib/esm/monaco.contribution",
         "monaco-yaml/lib/esm/yaml.worker",
-        "rxjs/_esm5/internal/OuterSubscriber",
-        "rxjs/_esm5/internal/util/subscribeToResult",
-        "rxjs/_esm5/internal/util/subscribeToArray",
-        "rxjs/_esm5/internal/Observable",
     ],
     format = "cjs",
     platform = "node",
diff --git a/client/web/dev/esbuild/config.ts b/client/web/dev/esbuild/config.ts
index 596dc586911..ffe0e90d368 100644
--- a/client/web/dev/esbuild/config.ts
+++ b/client/web/dev/esbuild/config.ts
@@ -8,7 +8,6 @@ import {
     stylePlugin,
     packageResolutionPlugin,
     monacoPlugin,
-    RXJS_RESOLUTIONS,
     buildTimerPlugin,
     workerPlugin,
 } from '@sourcegraph/build-config/src/esbuild/plugins'
@@ -51,7 +50,6 @@ export function esbuildBuildOptions(ENVIRONMENT_CONFIG: EnvironmentConfig): esbu
             workerPlugin,
             packageResolutionPlugin({
                 path: require.resolve('path-browserify'),
-                ...RXJS_RESOLUTIONS,
                 ...(ENVIRONMENT_CONFIG.DEV_WEB_BUILDER_OMIT_SLOW_DEPS
                     ? {
                           // Monaco
diff --git a/client/web/src/SearchQueryStateObserver.tsx b/client/web/src/SearchQueryStateObserver.tsx
index d6710ddb0a1..4610a1a3d30 100644
--- a/client/web/src/SearchQueryStateObserver.tsx
+++ b/client/web/src/SearchQueryStateObserver.tsx
@@ -1,8 +1,7 @@
 import { type FC, useLayoutEffect, useRef, useState } from 'react'
 
 import { type Location, useLocation } from 'react-router-dom'
-import { BehaviorSubject } from 'rxjs'
-import { first } from 'rxjs/operators'
+import { BehaviorSubject, firstValueFrom } from 'rxjs'
 
 import type { PlatformContext } from '@sourcegraph/shared/src/platform/context'
 import { isSearchContextSpecAvailable } from '@sourcegraph/shared/src/search'
@@ -45,12 +44,13 @@ export const SearchQueryStateObserver: FC<SearchQueryStateObserverProps> = props
             location: locationSubject,
             isSearchContextAvailable: (searchContext: string) =>
                 searchContextsEnabled
-                    ? isSearchContextSpecAvailable({
-                          spec: searchContext,
-                          platformContext,
-                      })
-                          .pipe(first())
-                          .toPromise()
+                    ? firstValueFrom(
+                          isSearchContextSpecAvailable({
+                              spec: searchContext,
+                              platformContext,
+                          }),
+                          { defaultValue: false }
+                      )
                     : Promise.resolve(false),
         }).subscribe(parsedSearchURLAndContext => {
             if (parsedSearchURLAndContext.query) {
diff --git a/client/web/src/components/externalServices/backend.ts b/client/web/src/components/externalServices/backend.ts
index 5ab2a4fbd0d..b46038b96fa 100644
--- a/client/web/src/components/externalServices/backend.ts
+++ b/client/web/src/components/externalServices/backend.ts
@@ -2,7 +2,7 @@ import type { Dispatch, SetStateAction } from 'react'
 
 import type { QueryTuple, MutationTuple, QueryResult } from '@apollo/client'
 import { parse } from 'jsonc-parser'
-import type { Observable } from 'rxjs'
+import { type Observable, lastValueFrom } from 'rxjs'
 import { map } from 'rxjs/operators'
 
 import { createAggregateError } from '@sourcegraph/common'
@@ -111,28 +111,30 @@ export const useUpdateExternalService = (
 export function updateExternalService(
     variables: UpdateExternalServiceVariables
 ): Promise<UpdateExternalServiceResult['updateExternalService']> {
-    return requestGraphQL<UpdateExternalServiceResult, UpdateExternalServiceVariables>(
-        UPDATE_EXTERNAL_SERVICE,
-        variables
-    )
-        .pipe(
+    return lastValueFrom(
+        requestGraphQL<UpdateExternalServiceResult, UpdateExternalServiceVariables>(
+            UPDATE_EXTERNAL_SERVICE,
+            variables
+        ).pipe(
             map(dataOrThrowErrors),
             map(data => data.updateExternalService)
         )
-        .toPromise()
+    )
 }
 
 export async function deleteExternalService(externalService: Scalars['ID']): Promise<void> {
-    const result = await requestGraphQL<DeleteExternalServiceResult, DeleteExternalServiceVariables>(
-        gql`
-            mutation DeleteExternalService($externalService: ID!) {
-                deleteExternalService(externalService: $externalService) {
-                    alwaysNil
+    const result = await lastValueFrom(
+        requestGraphQL<DeleteExternalServiceResult, DeleteExternalServiceVariables>(
+            gql`
+                mutation DeleteExternalService($externalService: ID!) {
+                    deleteExternalService(externalService: $externalService) {
+                        alwaysNil
+                    }
                 }
-            }
-        `,
-        { externalService }
-    ).toPromise()
+            `,
+            { externalService }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
diff --git a/client/web/src/enterprise/batches/close/backend.ts b/client/web/src/enterprise/batches/close/backend.ts
index 5730b884c65..bfbb716595e 100644
--- a/client/web/src/enterprise/batches/close/backend.ts
+++ b/client/web/src/enterprise/batches/close/backend.ts
@@ -1,18 +1,22 @@
+import { lastValueFrom } from 'rxjs'
+
 import { gql, dataOrThrowErrors } from '@sourcegraph/http-client'
 
 import { requestGraphQL } from '../../../backend/graphql'
 import type { CloseBatchChangeResult, CloseBatchChangeVariables } from '../../../graphql-operations'
 
 export async function closeBatchChange({ batchChange, closeChangesets }: CloseBatchChangeVariables): Promise<void> {
-    const result = await requestGraphQL<CloseBatchChangeResult, CloseBatchChangeVariables>(
-        gql`
-            mutation CloseBatchChange($batchChange: ID!, $closeChangesets: Boolean) {
-                closeBatchChange(batchChange: $batchChange, closeChangesets: $closeChangesets) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<CloseBatchChangeResult, CloseBatchChangeVariables>(
+            gql`
+                mutation CloseBatchChange($batchChange: ID!, $closeChangesets: Boolean) {
+                    closeBatchChange(batchChange: $batchChange, closeChangesets: $closeChangesets) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, closeChangesets }
-    ).toPromise()
+            `,
+            { batchChange, closeChangesets }
+        )
+    )
     dataOrThrowErrors(result)
 }
diff --git a/client/web/src/enterprise/batches/detail/backend.ts b/client/web/src/enterprise/batches/detail/backend.ts
index 3229d8ad5d0..3ae3ae73beb 100644
--- a/client/web/src/enterprise/batches/detail/backend.ts
+++ b/client/web/src/enterprise/batches/detail/backend.ts
@@ -1,5 +1,5 @@
 import type { QueryResult, QueryTuple } from '@apollo/client'
-import { EMPTY, type Observable } from 'rxjs'
+import { EMPTY, lastValueFrom, type Observable } from 'rxjs'
 import { expand, map, reduce } from 'rxjs/operators'
 
 import { dataOrThrowErrors, gql, useLazyQuery, useQuery } from '@sourcegraph/http-client'
@@ -459,37 +459,39 @@ export const queryChangesets = ({
     )
 
 export async function syncChangeset(changeset: Scalars['ID']): Promise<void> {
-    const result = await requestGraphQL<SyncChangesetResult, SyncChangesetVariables>(
-        gql`
-            mutation SyncChangeset($changeset: ID!) {
-                syncChangeset(changeset: $changeset) {
-                    alwaysNil
+    const result = await lastValueFrom(
+        requestGraphQL<SyncChangesetResult, SyncChangesetVariables>(
+            gql`
+                mutation SyncChangeset($changeset: ID!) {
+                    syncChangeset(changeset: $changeset) {
+                        alwaysNil
+                    }
                 }
-            }
-        `,
-        { changeset }
-    ).toPromise()
+            `,
+            { changeset }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
 export async function reenqueueChangeset(changeset: Scalars['ID']): Promise<ChangesetFields> {
-    return requestGraphQL<ReenqueueChangesetResult, ReenqueueChangesetVariables>(
-        gql`
-            mutation ReenqueueChangeset($changeset: ID!) {
-                reenqueueChangeset(changeset: $changeset) {
-                    ...ChangesetFields
+    return lastValueFrom(
+        requestGraphQL<ReenqueueChangesetResult, ReenqueueChangesetVariables>(
+            gql`
+                mutation ReenqueueChangeset($changeset: ID!) {
+                    reenqueueChangeset(changeset: $changeset) {
+                        ...ChangesetFields
+                    }
                 }
-            }
 
-            ${changesetFieldsFragment}
-        `,
-        { changeset }
-    )
-        .pipe(
+                ${changesetFieldsFragment}
+            `,
+            { changeset }
+        ).pipe(
             map(dataOrThrowErrors),
             map(data => data.reenqueueChangeset)
         )
-        .toPromise()
+    )
 }
 
 // Because thats the name in the API:
@@ -628,16 +630,18 @@ export const useChangesetCountsOverTime = (
     })
 
 export async function deleteBatchChange(batchChange: Scalars['ID']): Promise<void> {
-    const result = await requestGraphQL<DeleteBatchChangeResult, DeleteBatchChangeVariables>(
-        gql`
-            mutation DeleteBatchChange($batchChange: ID!) {
-                deleteBatchChange(batchChange: $batchChange) {
-                    alwaysNil
+    const result = await lastValueFrom(
+        requestGraphQL<DeleteBatchChangeResult, DeleteBatchChangeVariables>(
+            gql`
+                mutation DeleteBatchChange($batchChange: ID!) {
+                    deleteBatchChange(batchChange: $batchChange) {
+                        alwaysNil
+                    }
                 }
-            }
-        `,
-        { batchChange }
-    ).toPromise()
+            `,
+            { batchChange }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
@@ -657,20 +661,20 @@ const changesetDiffFragment = gql`
 `
 
 export async function getChangesetDiff(changeset: Scalars['ID']): Promise<string> {
-    return requestGraphQL<ChangesetDiffResult, ChangesetDiffVariables>(
-        gql`
-            query ChangesetDiff($changeset: ID!) {
-                node(id: $changeset) {
-                    __typename
-                    ...ChangesetDiffFields
+    return lastValueFrom(
+        requestGraphQL<ChangesetDiffResult, ChangesetDiffVariables>(
+            gql`
+                query ChangesetDiff($changeset: ID!) {
+                    node(id: $changeset) {
+                        __typename
+                        ...ChangesetDiffFields
+                    }
                 }
-            }
 
-            ${changesetDiffFragment}
-        `,
-        { changeset }
-    )
-        .pipe(
+                ${changesetDiffFragment}
+            `,
+            { changeset }
+        ).pipe(
             map(dataOrThrowErrors),
             map(({ node }) => {
                 if (!node) {
@@ -693,7 +697,7 @@ export async function getChangesetDiff(changeset: Scalars['ID']): Promise<string
                 return commits[0].diff
             })
         )
-        .toPromise()
+    )
 }
 
 const changesetScheduleEstimateFragment = gql`
@@ -703,20 +707,20 @@ const changesetScheduleEstimateFragment = gql`
 `
 
 export async function getChangesetScheduleEstimate(changeset: Scalars['ID']): Promise<Scalars['DateTime'] | null> {
-    return requestGraphQL<ChangesetScheduleEstimateResult, ChangesetScheduleEstimateVariables>(
-        gql`
-            query ChangesetScheduleEstimate($changeset: ID!) {
-                node(id: $changeset) {
-                    __typename
-                    ...ChangesetScheduleEstimateFields
+    return lastValueFrom(
+        requestGraphQL<ChangesetScheduleEstimateResult, ChangesetScheduleEstimateVariables>(
+            gql`
+                query ChangesetScheduleEstimate($changeset: ID!) {
+                    node(id: $changeset) {
+                        __typename
+                        ...ChangesetScheduleEstimateFields
+                    }
                 }
-            }
 
-            ${changesetScheduleEstimateFragment}
-        `,
-        { changeset }
-    )
-        .pipe(
+                ${changesetScheduleEstimateFragment}
+            `,
+            { changeset }
+        ).pipe(
             map(dataOrThrowErrors),
             map(({ node }) => {
                 if (!node) {
@@ -730,20 +734,22 @@ export async function getChangesetScheduleEstimate(changeset: Scalars['ID']): Pr
                 return node.scheduleEstimateAt
             })
         )
-        .toPromise()
+    )
 }
 
 export async function detachChangesets(batchChange: Scalars['ID'], changesets: Scalars['ID'][]): Promise<void> {
-    const result = await requestGraphQL<DetachChangesetsResult, DetachChangesetsVariables>(
-        gql`
-            mutation DetachChangesets($batchChange: ID!, $changesets: [ID!]!) {
-                detachChangesets(batchChange: $batchChange, changesets: $changesets) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<DetachChangesetsResult, DetachChangesetsVariables>(
+            gql`
+                mutation DetachChangesets($batchChange: ID!, $changesets: [ID!]!) {
+                    detachChangesets(batchChange: $batchChange, changesets: $changesets) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, changesets }
-    ).toPromise()
+            `,
+            { batchChange, changesets }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
@@ -752,30 +758,34 @@ export async function createChangesetComments(
     changesets: Scalars['ID'][],
     body: string
 ): Promise<void> {
-    const result = await requestGraphQL<CreateChangesetCommentsResult, CreateChangesetCommentsVariables>(
-        gql`
-            mutation CreateChangesetComments($batchChange: ID!, $changesets: [ID!]!, $body: String!) {
-                createChangesetComments(batchChange: $batchChange, changesets: $changesets, body: $body) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<CreateChangesetCommentsResult, CreateChangesetCommentsVariables>(
+            gql`
+                mutation CreateChangesetComments($batchChange: ID!, $changesets: [ID!]!, $body: String!) {
+                    createChangesetComments(batchChange: $batchChange, changesets: $changesets, body: $body) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, changesets, body }
-    ).toPromise()
+            `,
+            { batchChange, changesets, body }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
 export async function reenqueueChangesets(batchChange: Scalars['ID'], changesets: Scalars['ID'][]): Promise<void> {
-    const result = await requestGraphQL<ReenqueueChangesetsResult, ReenqueueChangesetsVariables>(
-        gql`
-            mutation ReenqueueChangesets($batchChange: ID!, $changesets: [ID!]!) {
-                reenqueueChangesets(batchChange: $batchChange, changesets: $changesets) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<ReenqueueChangesetsResult, ReenqueueChangesetsVariables>(
+            gql`
+                mutation ReenqueueChangesets($batchChange: ID!, $changesets: [ID!]!) {
+                    reenqueueChangesets(batchChange: $batchChange, changesets: $changesets) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, changesets }
-    ).toPromise()
+            `,
+            { batchChange, changesets }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
@@ -784,30 +794,34 @@ export async function mergeChangesets(
     changesets: Scalars['ID'][],
     squash: boolean
 ): Promise<void> {
-    const result = await requestGraphQL<MergeChangesetsResult, MergeChangesetsVariables>(
-        gql`
-            mutation MergeChangesets($batchChange: ID!, $changesets: [ID!]!, $squash: Boolean!) {
-                mergeChangesets(batchChange: $batchChange, changesets: $changesets, squash: $squash) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<MergeChangesetsResult, MergeChangesetsVariables>(
+            gql`
+                mutation MergeChangesets($batchChange: ID!, $changesets: [ID!]!, $squash: Boolean!) {
+                    mergeChangesets(batchChange: $batchChange, changesets: $changesets, squash: $squash) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, changesets, squash }
-    ).toPromise()
+            `,
+            { batchChange, changesets, squash }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
 export async function closeChangesets(batchChange: Scalars['ID'], changesets: Scalars['ID'][]): Promise<void> {
-    const result = await requestGraphQL<CloseChangesetsResult, CloseChangesetsVariables>(
-        gql`
-            mutation CloseChangesets($batchChange: ID!, $changesets: [ID!]!) {
-                closeChangesets(batchChange: $batchChange, changesets: $changesets) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<CloseChangesetsResult, CloseChangesetsVariables>(
+            gql`
+                mutation CloseChangesets($batchChange: ID!, $changesets: [ID!]!) {
+                    closeChangesets(batchChange: $batchChange, changesets: $changesets) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, changesets }
-    ).toPromise()
+            `,
+            { batchChange, changesets }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
@@ -816,16 +830,18 @@ export async function publishChangesets(
     changesets: Scalars['ID'][],
     draft: boolean
 ): Promise<void> {
-    const result = await requestGraphQL<PublishChangesetsResult, PublishChangesetsVariables>(
-        gql`
-            mutation PublishChangesets($batchChange: ID!, $changesets: [ID!]!, $draft: Boolean!) {
-                publishChangesets(batchChange: $batchChange, changesets: $changesets, draft: $draft) {
-                    id
+    const result = await lastValueFrom(
+        requestGraphQL<PublishChangesetsResult, PublishChangesetsVariables>(
+            gql`
+                mutation PublishChangesets($batchChange: ID!, $changesets: [ID!]!, $draft: Boolean!) {
+                    publishChangesets(batchChange: $batchChange, changesets: $changesets, draft: $draft) {
+                        id
+                    }
                 }
-            }
-        `,
-        { batchChange, changesets, draft }
-    ).toPromise()
+            `,
+            { batchChange, changesets, draft }
+        )
+    )
     dataOrThrowErrors(result)
 }
 
diff --git a/client/web/src/enterprise/batches/preview/backend.ts b/client/web/src/enterprise/batches/preview/backend.ts
index 1c56fea8dce..cadd6b49c04 100644
--- a/client/web/src/enterprise/batches/preview/backend.ts
+++ b/client/web/src/enterprise/batches/preview/backend.ts
@@ -1,4 +1,4 @@
-import type { Observable } from 'rxjs'
+import { lastValueFrom, type Observable } from 'rxjs'
 import { map } from 'rxjs/operators'
 
 import { gql, dataOrThrowErrors } from '@sourcegraph/http-client'
@@ -139,49 +139,49 @@ export const createBatchChange = ({
     batchSpec,
     publicationStates,
 }: CreateBatchChangeVariables): Promise<CreateBatchChangeResult['createBatchChange']> =>
-    requestGraphQL<CreateBatchChangeResult, CreateBatchChangeVariables>(
-        gql`
-            mutation CreateBatchChange($batchSpec: ID!, $publicationStates: [ChangesetSpecPublicationStateInput!]) {
-                createBatchChange(batchSpec: $batchSpec, publicationStates: $publicationStates) {
-                    id
-                    url
+    lastValueFrom(
+        requestGraphQL<CreateBatchChangeResult, CreateBatchChangeVariables>(
+            gql`
+                mutation CreateBatchChange($batchSpec: ID!, $publicationStates: [ChangesetSpecPublicationStateInput!]) {
+                    createBatchChange(batchSpec: $batchSpec, publicationStates: $publicationStates) {
+                        id
+                        url
+                    }
                 }
-            }
-        `,
-        { batchSpec, publicationStates }
-    )
-        .pipe(
+            `,
+            { batchSpec, publicationStates }
+        ).pipe(
             map(dataOrThrowErrors),
             map(data => data.createBatchChange)
         )
-        .toPromise()
+    )
 
 export const applyBatchChange = ({
     batchSpec,
     batchChange,
     publicationStates,
 }: ApplyBatchChangeVariables): Promise<ApplyBatchChangeResult['applyBatchChange']> =>
-    requestGraphQL<ApplyBatchChangeResult, ApplyBatchChangeVariables>(
-        gql`
-            mutation ApplyBatchChange(
-                $batchSpec: ID!
-                $batchChange: ID!
-                $publicationStates: [ChangesetSpecPublicationStateInput!]
-            ) {
-                applyBatchChange(
-                    batchSpec: $batchSpec
-                    ensureBatchChange: $batchChange
-                    publicationStates: $publicationStates
+    lastValueFrom(
+        requestGraphQL<ApplyBatchChangeResult, ApplyBatchChangeVariables>(
+            gql`
+                mutation ApplyBatchChange(
+                    $batchSpec: ID!
+                    $batchChange: ID!
+                    $publicationStates: [ChangesetSpecPublicationStateInput!]
                 ) {
-                    id
-                    url
+                    applyBatchChange(
+                        batchSpec: $batchSpec
+                        ensureBatchChange: $batchChange
+                        publicationStates: $publicationStates
+                    ) {
+                        id
+                        url
+                    }
                 }
-            }
-        `,
-        { batchSpec, batchChange, publicationStates }
-    )
-        .pipe(
+            `,
+            { batchSpec, batchChange, publicationStates }
+        ).pipe(
             map(dataOrThrowErrors),
             map(data => data.applyBatchChange)
         )
-        .toPromise()
+    )
diff --git a/client/web/src/enterprise/codeintel/indexes/components/EnqueueForm.tsx b/client/web/src/enterprise/codeintel/indexes/components/EnqueueForm.tsx
index 7362d418cec..ad4a430ab81 100644
--- a/client/web/src/enterprise/codeintel/indexes/components/EnqueueForm.tsx
+++ b/client/web/src/enterprise/codeintel/indexes/components/EnqueueForm.tsx
@@ -41,8 +41,8 @@ export const EnqueueForm: FunctionComponent<EnqueueFormProps> = ({
 
             const queueResultLength = indexes?.queueAutoIndexJobsForRepo.length || 0
             setQueueResult(queueResultLength)
-            if (queueResultLength > 0) {
-                querySubject.next(indexes?.queueAutoIndexJobsForRepo[0].inputCommit)
+            if (queueResultLength > 0 && indexes?.queueAutoIndexJobsForRepo[0].inputCommit !== undefined) {
+                querySubject.next(indexes.queueAutoIndexJobsForRepo[0].inputCommit)
             }
         } catch (error) {
             setEnqueueError(error)
diff --git a/client/web/src/enterprise/codeintel/indexes/pages/CodeIntelPreciseIndexesPage.tsx b/client/web/src/enterprise/codeintel/indexes/pages/CodeIntelPreciseIndexesPage.tsx
index 197dcba5916..eae35f829e4 100644
--- a/client/web/src/enterprise/codeintel/indexes/pages/CodeIntelPreciseIndexesPage.tsx
+++ b/client/web/src/enterprise/codeintel/indexes/pages/CodeIntelPreciseIndexesPage.tsx
@@ -170,7 +170,7 @@ export const CodeIntelPreciseIndexesPage: FunctionComponent<CodeIntelPreciseInde
     }, [indexerData?.indexerKeys])
 
     // Poke filtered connection to refresh
-    const refresh = useMemo(() => new Subject<undefined>(), [])
+    const refresh = useMemo(() => new Subject<void>(), [])
     const querySubject = useMemo(() => new Subject<string>(), [])
 
     // State used to control bulk index selection
diff --git a/client/web/src/enterprise/insights/core/hooks/live-preview-insight/use-live-preview-lang-stats-insight.ts b/client/web/src/enterprise/insights/core/hooks/live-preview-insight/use-live-preview-lang-stats-insight.ts
index 1031ffbcdb6..708a11e474b 100644
--- a/client/web/src/enterprise/insights/core/hooks/live-preview-insight/use-live-preview-lang-stats-insight.ts
+++ b/client/web/src/enterprise/insights/core/hooks/live-preview-insight/use-live-preview-lang-stats-insight.ts
@@ -122,7 +122,7 @@ async function getLangStats(inputs: GetInsightContentInputs): Promise<Categorica
         )
         .toPromise()
 
-    if (stats.languages.length === 0) {
+    if (!stats || stats.languages.length === 0) {
         throw new Error("We couldn't find the language statistics, try changing the repository.")
     }
 
diff --git a/client/web/src/enterprise/insights/pages/dashboards/creation/InsightsDashboardCreationPage.tsx b/client/web/src/enterprise/insights/pages/dashboards/creation/InsightsDashboardCreationPage.tsx
index d21015cd49b..6a9ffab80a4 100644
--- a/client/web/src/enterprise/insights/pages/dashboards/creation/InsightsDashboardCreationPage.tsx
+++ b/client/web/src/enterprise/insights/pages/dashboards/creation/InsightsDashboardCreationPage.tsx
@@ -2,6 +2,7 @@ import React, { useContext, useMemo } from 'react'
 
 import classNames from 'classnames'
 import { useNavigate } from 'react-router-dom'
+import { lastValueFrom } from 'rxjs'
 
 import type { TelemetryProps } from '@sourcegraph/shared/src/telemetry/telemetryService'
 import { PageHeader, Container, Button, LoadingSpinner, useObservable, Link, Tooltip } from '@sourcegraph/wildcard'
@@ -40,7 +41,7 @@ export const InsightsDashboardCreationPage: React.FunctionComponent<
             throw new Error('You have to specify a dashboard visibility')
         }
 
-        const createdDashboard = await createDashboard({ name, owners: [owner] }).toPromise()
+        const createdDashboard = await lastValueFrom(createDashboard({ name, owners: [owner] }))
 
         telemetryService.log('CodeInsightsDashboardCreationPageSubmitClick')
 
diff --git a/client/web/src/enterprise/insights/pages/dashboards/edit-dashboard/EditDashobardPage.tsx b/client/web/src/enterprise/insights/pages/dashboards/edit-dashboard/EditDashobardPage.tsx
index e5030cdbcb0..7b5c896010b 100644
--- a/client/web/src/enterprise/insights/pages/dashboards/edit-dashboard/EditDashobardPage.tsx
+++ b/client/web/src/enterprise/insights/pages/dashboards/edit-dashboard/EditDashobardPage.tsx
@@ -3,6 +3,7 @@ import { type FC, useContext, useMemo } from 'react'
 import classNames from 'classnames'
 import MapSearchIcon from 'mdi-react/MapSearchIcon'
 import { useParams, useNavigate } from 'react-router-dom'
+import { lastValueFrom } from 'rxjs'
 
 import {
     Button,
@@ -70,13 +71,15 @@ export const EditDashboardPage: FC = props => {
             throw new Error('You have to specify a dashboard visibility')
         }
 
-        const updatedDashboard = await updateDashboard({
-            id: dashboard.id,
-            nextDashboardInput: {
-                name,
-                owners: [owner],
-            },
-        }).toPromise()
+        const updatedDashboard = await lastValueFrom(
+            updateDashboard({
+                id: dashboard.id,
+                nextDashboardInput: {
+                    name,
+                    owners: [owner],
+                },
+            })
+        )
 
         navigate(`/insights/dashboards/${updatedDashboard.id}`)
     }
diff --git a/client/web/src/enterprise/searchContexts/backend.ts b/client/web/src/enterprise/searchContexts/backend.ts
index a700f202c84..1e6f9439b78 100644
--- a/client/web/src/enterprise/searchContexts/backend.ts
+++ b/client/web/src/enterprise/searchContexts/backend.ts
@@ -1,5 +1,6 @@
+import { lastValueFrom } from 'rxjs'
+
 import { dataOrThrowErrors, gql } from '@sourcegraph/http-client'
-import type { GraphQLResult } from '@sourcegraph/http-client'
 
 import { requestGraphQL } from '../../backend/graphql'
 import type { InputMaybe, RepositoriesByNamesResult, RepositoriesByNamesVariables } from '../../graphql-operations'
@@ -27,14 +28,13 @@ export async function fetchRepositoriesByNames(
     let after: InputMaybe<string> = null
 
     while (true) {
-        const result: GraphQLResult<RepositoriesByNamesResult> = await requestGraphQL<
-            RepositoriesByNamesResult,
-            RepositoriesByNamesVariables
-        >(query, {
-            names,
-            first,
-            after,
-        }).toPromise()
+        const result = await lastValueFrom(
+            requestGraphQL<RepositoriesByNamesResult, RepositoriesByNamesVariables>(query, {
+                names,
+                first,
+                after,
+            })
+        )
 
         const data: RepositoriesByNamesResult = dataOrThrowErrors(result)
 
diff --git a/client/web/src/org/backend.ts b/client/web/src/org/backend.ts
index f9099a25a92..8cf14bb64b4 100644
--- a/client/web/src/org/backend.ts
+++ b/client/web/src/org/backend.ts
@@ -1,4 +1,4 @@
-import { concat, type Observable } from 'rxjs'
+import { concat, lastValueFrom, type Observable } from 'rxjs'
 import { map, mergeMap } from 'rxjs/operators'
 
 import { createAggregateError } from '@sourcegraph/common'
@@ -65,19 +65,19 @@ export function createOrganization(args: {
     /** The new organization's display name (e.g. full name) in the organization profile. */
     displayName?: string
 }): Promise<CreateOrganizationResult['createOrganization']> {
-    return requestGraphQL<CreateOrganizationResult, CreateOrganizationVariables>(
-        gql`
-            mutation CreateOrganization($name: String!, $displayName: String) {
-                createOrganization(name: $name, displayName: $displayName) {
-                    id
-                    name
-                    settingsURL
+    return lastValueFrom(
+        requestGraphQL<CreateOrganizationResult, CreateOrganizationVariables>(
+            gql`
+                mutation CreateOrganization($name: String!, $displayName: String) {
+                    createOrganization(name: $name, displayName: $displayName) {
+                        id
+                        name
+                        settingsURL
+                    }
                 }
-            }
-        `,
-        { name: args.name, displayName: args.displayName ?? null }
-    )
-        .pipe(
+            `,
+            { name: args.name, displayName: args.displayName ?? null }
+        ).pipe(
             mergeMap(({ data, errors }) => {
                 if (!data?.createOrganization) {
                     eventLogger.log('NewOrgFailed')
@@ -87,7 +87,7 @@ export function createOrganization(args: {
                 return concat(refreshAuthenticatedUser(), [data.createOrganization])
             })
         )
-        .toPromise()
+    )
 }
 
 export const REMOVE_USER_FROM_ORGANIZATION_QUERY = gql`
diff --git a/client/web/src/org/settings/members/InviteForm.tsx b/client/web/src/org/settings/members/InviteForm.tsx
index c4e2aa08ae2..4384442c644 100644
--- a/client/web/src/org/settings/members/InviteForm.tsx
+++ b/client/web/src/org/settings/members/InviteForm.tsx
@@ -2,6 +2,7 @@ import React, { useCallback, useState } from 'react'
 
 import { mdiPlus, mdiEmailOpenOutline, mdiClose } from '@mdi/js'
 import classNames from 'classnames'
+import { lastValueFrom } from 'rxjs'
 import { map } from 'rxjs/operators'
 
 import { asError, createAggregateError, isErrorLike } from '@sourcegraph/common'
@@ -204,25 +205,25 @@ function inviteUserToOrganization(
     username: string,
     organization: Scalars['ID']
 ): Promise<InviteUserToOrganizationResult['inviteUserToOrganization']> {
-    return requestGraphQL<InviteUserToOrganizationResult, InviteUserToOrganizationVariables>(
-        gql`
-            mutation InviteUserToOrganization($organization: ID!, $username: String!) {
-                inviteUserToOrganization(organization: $organization, username: $username) {
-                    ...InviteUserToOrganizationFields
+    return lastValueFrom(
+        requestGraphQL<InviteUserToOrganizationResult, InviteUserToOrganizationVariables>(
+            gql`
+                mutation InviteUserToOrganization($organization: ID!, $username: String!) {
+                    inviteUserToOrganization(organization: $organization, username: $username) {
+                        ...InviteUserToOrganizationFields
+                    }
                 }
-            }
 
-            fragment InviteUserToOrganizationFields on InviteUserToOrganizationResult {
-                sentInvitationEmail
-                invitationURL
+                fragment InviteUserToOrganizationFields on InviteUserToOrganizationResult {
+                    sentInvitationEmail
+                    invitationURL
+                }
+            `,
+            {
+                username,
+                organization,
             }
-        `,
-        {
-            username,
-            organization,
-        }
-    )
-        .pipe(
+        ).pipe(
             map(({ data, errors }) => {
                 if (!data?.inviteUserToOrganization || (errors && errors.length > 0)) {
                     eventLogger.log('InviteOrgMemberFailed')
@@ -232,7 +233,7 @@ function inviteUserToOrganization(
                 return data.inviteUserToOrganization
             })
         )
-        .toPromise()
+    )
 }
 
 function addUserToOrganization(username: string, organization: Scalars['ID']): Promise<void> {
diff --git a/client/web/src/regression/util/api.ts b/client/web/src/regression/util/api.ts
index 781a5569501..1b71e0f4e7b 100644
--- a/client/web/src/regression/util/api.ts
+++ b/client/web/src/regression/util/api.ts
@@ -2,7 +2,7 @@
  * Provides convenience functions for interacting with the Sourcegraph API from tests.
  */
 
-import { zip, timer, concat, throwError, defer, type Observable } from 'rxjs'
+import { zip, timer, concat, throwError, defer, type Observable, lastValueFrom } from 'rxjs'
 import { map, tap, retryWhen, delayWhen, take, mergeMap } from 'rxjs/operators'
 
 import { isErrorLike, createAggregateError, logger } from '@sourcegraph/common'
@@ -261,40 +261,41 @@ export function getExternalServices(
         uniqueDisplayName?: string
     } = {}
 ): Promise<ExternalServiceNodeFields[]> {
-    return gqlClient
-        .queryGraphQL<ExternalServicesRegressionResult, ExternalServicesRegressionVariables>(
-            gql`
-                query ExternalServicesRegression($first: Int) {
-                    externalServices(first: $first) {
-                        nodes {
-                            ...ExternalServiceNodeFields
+    return lastValueFrom(
+        gqlClient
+            .queryGraphQL<ExternalServicesRegressionResult, ExternalServicesRegressionVariables>(
+                gql`
+                    query ExternalServicesRegression($first: Int) {
+                        externalServices(first: $first) {
+                            nodes {
+                                ...ExternalServiceNodeFields
+                            }
                         }
                     }
-                }
 
-                fragment ExternalServiceNodeFields on ExternalService {
-                    id
-                    kind
-                    displayName
-                    config
-                    createdAt
-                    updatedAt
-                    warning
-                }
-            `,
-            { first: 100 }
-        )
-        .pipe(
-            map(dataOrThrowErrors),
-            map(({ externalServices }) =>
-                externalServices.nodes.filter(
-                    ({ displayName, kind }) =>
-                        (options.uniqueDisplayName === undefined || options.uniqueDisplayName === displayName) &&
-                        (options.kind === undefined || options.kind === kind)
+                    fragment ExternalServiceNodeFields on ExternalService {
+                        id
+                        kind
+                        displayName
+                        config
+                        createdAt
+                        updatedAt
+                        warning
+                    }
+                `,
+                { first: 100 }
+            )
+            .pipe(
+                map(dataOrThrowErrors),
+                map(({ externalServices }) =>
+                    externalServices.nodes.filter(
+                        ({ displayName, kind }) =>
+                            (options.uniqueDisplayName === undefined || options.uniqueDisplayName === displayName) &&
+                            (options.kind === undefined || options.kind === kind)
+                    )
                 )
             )
-        )
-        .toPromise()
+    )
 }
 
 export async function updateExternalService(
@@ -448,22 +449,23 @@ export async function setTosAccepted(gqlClient: GraphQLClient, userID: Scalars['
  * dependency-injected `requestGraphQL`.
  */
 export function currentProductVersion(gqlClient: GraphQLClient): Promise<string> {
-    return gqlClient
-        .queryGraphQL<SiteProductVersionResult, SiteProductVersionVariables>(
-            gql`
-                query SiteProductVersion {
-                    site {
-                        productVersion
+    return lastValueFrom(
+        gqlClient
+            .queryGraphQL<SiteProductVersionResult, SiteProductVersionVariables>(
+                gql`
+                    query SiteProductVersion {
+                        site {
+                            productVersion
+                        }
                     }
-                }
-            `,
-            {}
-        )
-        .pipe(
-            map(dataOrThrowErrors),
-            map(({ site }) => site.productVersion)
-        )
-        .toPromise()
+                `,
+                {}
+            )
+            .pipe(
+                map(dataOrThrowErrors),
+                map(({ site }) => site.productVersion)
+            )
+    )
 }
 
 /**
@@ -473,16 +475,16 @@ export function currentProductVersion(gqlClient: GraphQLClient): Promise<string>
 export function getViewerSettings({
     requestGraphQL,
 }: Pick<PlatformContext, 'requestGraphQL'>): Promise<ViewerSettingsResult['viewerSettings']> {
-    return requestGraphQL<ViewerSettingsResult, ViewerSettingsVariables>({
-        request: viewerSettingsQuery,
-        variables: {},
-        mightContainPrivateInfo: true,
-    })
-        .pipe(
+    return lastValueFrom(
+        requestGraphQL<ViewerSettingsResult, ViewerSettingsVariables>({
+            request: viewerSettingsQuery,
+            variables: {},
+            mightContainPrivateInfo: true,
+        }).pipe(
             map(dataOrThrowErrors),
             map(data => data.viewerSettings)
         )
-        .toPromise()
+    )
 }
 
 /**
@@ -631,55 +633,54 @@ export function createUser(
  * TODO(beyang): remove this after the corresponding API in the main code has been updated to use a
  * dependency-injected `requestGraphQL`.
  */
-export async function getUser(
+export function getUser(
     { requestGraphQL }: Pick<PlatformContext, 'requestGraphQL'>,
     username: string
 ): Promise<UserResult['user']> {
-    const user = await requestGraphQL<UserResult, UserVariables>({
-        request: gql`
-            query User($username: String!) {
-                user(username: $username) {
-                    __typename
-                    id
-                    username
-                    displayName
-                    url
-                    settingsURL
-                    avatarURL
-                    viewerCanAdminister
-                    siteAdmin
-                    createdAt
-                    emails {
-                        email
-                        verified
-                    }
-                    organizations {
-                        nodes {
-                            id
-                            displayName
-                            name
+    return lastValueFrom(
+        requestGraphQL<UserResult, UserVariables>({
+            request: gql`
+                query User($username: String!) {
+                    user(username: $username) {
+                        __typename
+                        id
+                        username
+                        displayName
+                        url
+                        settingsURL
+                        avatarURL
+                        viewerCanAdminister
+                        siteAdmin
+                        createdAt
+                        emails {
+                            email
+                            verified
                         }
-                    }
-                    settingsCascade {
-                        subjects {
-                            latestSettings {
+                        organizations {
+                            nodes {
                                 id
-                                contents
+                                displayName
+                                name
+                            }
+                        }
+                        settingsCascade {
+                            subjects {
+                                latestSettings {
+                                    id
+                                    contents
+                                }
                             }
                         }
                     }
                 }
-            }
-        `,
-        variables: { username },
-        mightContainPrivateInfo: true,
-    })
-        .pipe(
+            `,
+            variables: { username },
+            mightContainPrivateInfo: true,
+        }).pipe(
             map(dataOrThrowErrors),
             map(({ user }) => user)
         )
-        .toPromise()
-    return user
+    )
 }
 
 /**
@@ -748,86 +749,86 @@ export function search(
     version: SearchVersion,
     patternType: SearchPatternType
 ): Promise<SearchResult['search']> {
-    return requestGraphQL<SearchResult, SearchVariables>({
-        request: gql`
-            query Search($query: String!, $version: SearchVersion!, $patternType: SearchPatternType!) {
-                search(query: $query, version: $version, patternType: $patternType) {
-                    results {
-                        __typename
-                        limitHit
-                        matchCount
-                        approximateResultCount
-                        missing {
-                            name
-                        }
-                        cloning {
-                            name
-                        }
-                        timedout {
-                            name
-                        }
-                        indexUnavailable
-                        dynamicFilters {
-                            value
-                            label
-                            count
-                            limitHit
-                            kind
-                        }
+    return lastValueFrom(
+        requestGraphQL<SearchResult, SearchVariables>({
+            request: gql`
+                query Search($query: String!, $version: SearchVersion!, $patternType: SearchPatternType!) {
+                    search(query: $query, version: $version, patternType: $patternType) {
                         results {
                             __typename
-                            ... on Repository {
-                                id
+                            limitHit
+                            matchCount
+                            approximateResultCount
+                            missing {
                                 name
-                                ...GenericSearchResultFields
                             }
-                            ... on FileMatch {
-                                file {
-                                    path
-                                    url
-                                    commit {
-                                        oid
+                            cloning {
+                                name
+                            }
+                            timedout {
+                                name
+                            }
+                            indexUnavailable
+                            dynamicFilters {
+                                value
+                                label
+                                count
+                                limitHit
+                                kind
+                            }
+                            results {
+                                __typename
+                                ... on Repository {
+                                    id
+                                    name
+                                    ...GenericSearchResultFields
+                                }
+                                ... on FileMatch {
+                                    file {
+                                        path
+                                        url
+                                        commit {
+                                            oid
+                                        }
+                                    }
+                                    repository {
+                                        name
+                                        url
+                                    }
+                                    limitHit
+                                    symbols {
+                                        name
+                                        containerName
+                                        url
+                                        kind
+                                    }
+                                    lineMatches {
+                                        preview
+                                        lineNumber
+                                        offsetAndLengths
                                     }
                                 }
-                                repository {
-                                    name
-                                    url
-                                }
-                                limitHit
-                                symbols {
-                                    name
-                                    containerName
-                                    url
-                                    kind
-                                }
-                                lineMatches {
-                                    preview
-                                    lineNumber
-                                    offsetAndLengths
+                                ... on CommitSearchResult {
+                                    ...GenericSearchResultFields
                                 }
                             }
-                            ... on CommitSearchResult {
-                                ...GenericSearchResultFields
-                            }
-                        }
-                        alert {
-                            title
-                            description
-                            proposedQueries {
+                            alert {
+                                title
                                 description
-                                query
+                                proposedQueries {
+                                    description
+                                    query
+                                }
                             }
+                            elapsedMilliseconds
                         }
-                        elapsedMilliseconds
                     }
                 }
-            }
-            ${GenericSearchResultInterfaceFragment}
-        `,
-        variables: { query, version, patternType },
-        mightContainPrivateInfo: false,
-    })
-        .pipe(
+                ${GenericSearchResultInterfaceFragment}
+            `,
+            variables: { query, version, patternType },
+            mightContainPrivateInfo: false,
+        }).pipe(
             map(dataOrThrowErrors),
             map(data => {
                 if (!data.search) {
@@ -836,7 +837,7 @@ export function search(
                 return data.search
             })
         )
-        .toPromise()
+    )
 }
 
 /**
diff --git a/client/web/src/regression/util/helpers.ts b/client/web/src/regression/util/helpers.ts
index d14d853f2f1..a8aafe08162 100644
--- a/client/web/src/regression/util/helpers.ts
+++ b/client/web/src/regression/util/helpers.ts
@@ -1,6 +1,6 @@
 import * as jsonc from 'jsonc-parser'
 import { first } from 'lodash'
-import { throwError } from 'rxjs'
+import { lastValueFrom, throwError } from 'rxjs'
 import { catchError, map } from 'rxjs/operators'
 import { Key } from 'ts-key-enum'
 
@@ -131,7 +131,7 @@ export async function createAuthProvider(
     gqlClient: GraphQLClient,
     authProvider: GitHubAuthProvider | GitLabAuthProvider | OpenIDConnectAuthProvider | SAMLAuthProvider
 ): Promise<ResourceDestructor> {
-    const siteConfig = await fetchSiteConfiguration(gqlClient).toPromise()
+    const siteConfig = await lastValueFrom(fetchSiteConfiguration(gqlClient))
     const siteConfigParsed: SiteConfiguration = jsonc.parse(siteConfig.configuration.effectiveContents)
     const authProviders = siteConfigParsed['auth.providers']
     if (
@@ -185,7 +185,7 @@ export async function ensureNewOrganization(
     { requestGraphQL }: Pick<PlatformContext, 'requestGraphQL'>,
     variables: CreateOrganizationVariables
 ): Promise<{ destroy: ResourceDestructor; result: CreateOrganizationResult['createOrganization'] }> {
-    const matchingOrgs = (await fetchAllOrganizations({ requestGraphQL }, { first: 1000 }).toPromise()).nodes.filter(
+    const matchingOrgs = (await lastValueFrom(fetchAllOrganizations({ requestGraphQL }, { first: 1000 }))).nodes.filter(
         org => org.name === variables.name
     )
     if (matchingOrgs.length > 1) {
@@ -194,7 +194,7 @@ export async function ensureNewOrganization(
     if (matchingOrgs.length === 1) {
         await deleteOrganization({ requestGraphQL }, matchingOrgs[0].id).toPromise()
     }
-    const createdOrg = await createOrganization({ requestGraphQL }, variables).toPromise()
+    const createdOrg = await lastValueFrom(createOrganization({ requestGraphQL }, variables))
     return {
         destroy: () => deleteOrganization({ requestGraphQL }, createdOrg.id).toPromise(),
         result: createdOrg,
@@ -239,15 +239,15 @@ export async function editSiteConfig(
     gqlClient: GraphQLClient,
     ...edits: ((contents: string) => jsonc.Edit[])[]
 ): Promise<{ destroy: ResourceDestructor; result: boolean }> {
-    const origConfig = await fetchSiteConfiguration(gqlClient).toPromise()
+    const origConfig = await lastValueFrom(fetchSiteConfiguration(gqlClient))
     let newContents = origConfig.configuration.effectiveContents
     for (const editFunc of edits) {
         newContents = jsonc.applyEdits(newContents, editFunc(newContents))
     }
     return {
-        result: await updateSiteConfiguration(gqlClient, origConfig.configuration.id, newContents).toPromise(),
+        result: await lastValueFrom(updateSiteConfiguration(gqlClient, origConfig.configuration.id, newContents)),
         destroy: async () => {
-            const site = await fetchSiteConfiguration(gqlClient).toPromise()
+            const site = await lastValueFrom(fetchSiteConfiguration(gqlClient))
             await updateSiteConfiguration(
                 gqlClient,
                 site.configuration.id,
diff --git a/client/web/src/repo/RepoContainer.tsx b/client/web/src/repo/RepoContainer.tsx
index 65ab0edec1d..42129a3b05e 100644
--- a/client/web/src/repo/RepoContainer.tsx
+++ b/client/web/src/repo/RepoContainer.tsx
@@ -175,7 +175,7 @@ export const RepoContainer: FC<RepoContainerProps> = props => {
                                     }
 
                                     if (isCloneInProgressErrorLike(error)) {
-                                        return of<ErrorLike>(asError(error))
+                                        return of(asError(error))
                                     }
 
                                     throw error
@@ -185,7 +185,7 @@ export const RepoContainer: FC<RepoContainerProps> = props => {
                     )
                     .pipe(
                         repeatUntil(value => !isCloneInProgressErrorLike(value), { delay: 1000 }),
-                        catchError(error => of<ErrorLike>(asError(error)))
+                        catchError(error => of(asError(error)))
                     ),
             [repoName, revision]
         )
diff --git a/client/web/src/repo/blame/useBlameHunks.ts b/client/web/src/repo/blame/useBlameHunks.ts
index 9cabd8abcbb..c7260b67fdb 100644
--- a/client/web/src/repo/blame/useBlameHunks.ts
+++ b/client/web/src/repo/blame/useBlameHunks.ts
@@ -3,7 +3,7 @@ import { useMemo } from 'react'
 import { EventStreamContentType, fetchEventSource } from '@microsoft/fetch-event-source'
 import { formatDistanceStrict } from 'date-fns'
 import { truncate } from 'lodash'
-import { Observable, of } from 'rxjs'
+import { Observable, lastValueFrom, of } from 'rxjs'
 import { catchError, map, throttleTime } from 'rxjs/operators'
 
 import { type ErrorLike, memoizeObservable } from '@sourcegraph/common'
@@ -192,25 +192,25 @@ const fetchBlameViaStreaming = memoizeObservable(
 )
 
 async function fetchRepositoryData(repoName: string): Promise<Omit<BlameHunkData, 'current'>> {
-    return requestGraphQL<FirstCommitDateResult, FirstCommitDateVariables>(
-        gql`
-            query FirstCommitDate($repo: String!) {
-                repository(name: $repo) {
-                    firstEverCommit {
-                        author {
-                            date
+    return lastValueFrom(
+        requestGraphQL<FirstCommitDateResult, FirstCommitDateVariables>(
+            gql`
+                query FirstCommitDate($repo: String!) {
+                    repository(name: $repo) {
+                        firstEverCommit {
+                            author {
+                                date
+                            }
+                        }
+                        externalURLs {
+                            url
+                            serviceKind
                         }
                     }
-                    externalURLs {
-                        url
-                        serviceKind
-                    }
                 }
-            }
-        `,
-        { repo: repoName }
-    )
-        .pipe(
+            `,
+            { repo: repoName }
+        ).pipe(
             map(dataOrThrowErrors),
             map(({ repository }) => {
                 const firstCommitDate = repository?.firstEverCommit?.author?.date
@@ -220,7 +220,7 @@ async function fetchRepositoryData(repoName: string): Promise<Omit<BlameHunkData
                 }
             })
         )
-        .toPromise()
+    )
 }
 
 /**
diff --git a/client/web/src/repo/blob/actions/ToggleHistoryPanel.tsx b/client/web/src/repo/blob/actions/ToggleHistoryPanel.tsx
index 5c93a2c14ed..1f26e7d391e 100644
--- a/client/web/src/repo/blob/actions/ToggleHistoryPanel.tsx
+++ b/client/web/src/repo/blob/actions/ToggleHistoryPanel.tsx
@@ -33,7 +33,7 @@ export class ToggleHistoryPanel extends React.PureComponent<
         navigate: NavigateFunction
     } & RepoHeaderContext
 > {
-    private toggles = new Subject<boolean>()
+    private toggles = new Subject<void>()
     private subscriptions = new Subscription()
 
     /**
diff --git a/client/web/src/repo/settings/RepoSettingsArea.tsx b/client/web/src/repo/settings/RepoSettingsArea.tsx
index 84aff5f45c7..8823b18474b 100644
--- a/client/web/src/repo/settings/RepoSettingsArea.tsx
+++ b/client/web/src/repo/settings/RepoSettingsArea.tsx
@@ -7,7 +7,7 @@ import { Routes, Route } from 'react-router-dom'
 import { of } from 'rxjs'
 import { catchError } from 'rxjs/operators'
 
-import { asError, type ErrorLike, isErrorLike } from '@sourcegraph/common'
+import { asError, isErrorLike } from '@sourcegraph/common'
 import type { TelemetryV2Props } from '@sourcegraph/shared/src/telemetry'
 import type { TelemetryProps } from '@sourcegraph/shared/src/telemetry/telemetryService'
 import { useObservable, ErrorMessage } from '@sourcegraph/wildcard'
@@ -46,10 +46,7 @@ export const RepoSettingsArea: React.FunctionComponent<React.PropsWithChildren<P
 }) => {
     const repoName = props.repoName
     const repoOrError = useObservable(
-        useMemo(
-            () => fetchSettingsAreaRepository(repoName).pipe(catchError(error => of<ErrorLike>(asError(error)))),
-            [repoName]
-        )
+        useMemo(() => fetchSettingsAreaRepository(repoName).pipe(catchError(error => of(asError(error)))), [repoName])
     )
 
     useBreadcrumb(useMemo(() => ({ key: 'settings', element: 'Settings' }), []))
diff --git a/client/web/src/site-admin/SiteAdminConfigurationPage.tsx b/client/web/src/site-admin/SiteAdminConfigurationPage.tsx
index 769c5f32956..cf77d12001e 100644
--- a/client/web/src/site-admin/SiteAdminConfigurationPage.tsx
+++ b/client/web/src/site-admin/SiteAdminConfigurationPage.tsx
@@ -4,7 +4,7 @@ import type { FC } from 'react'
 import { type ApolloClient, useApolloClient } from '@apollo/client'
 import classNames from 'classnames'
 import * as jsonc from 'jsonc-parser'
-import { Subject, Subscription } from 'rxjs'
+import { lastValueFrom, Subject, Subscription } from 'rxjs'
 import { delay, mergeMap, retryWhen, tap, timeout } from 'rxjs/operators'
 
 import { logger } from '@sourcegraph/common'
@@ -468,7 +468,7 @@ class SiteAdminConfigurationContent extends React.Component<Props, State> {
 
         let restartToApply = false
         try {
-            restartToApply = await updateSiteConfiguration(lastConfigurationID, newContents).toPromise<boolean>()
+            restartToApply = await lastValueFrom(updateSiteConfiguration(lastConfigurationID, newContents))
         } catch (error) {
             logger.error(error)
             this.setState({
@@ -512,7 +512,7 @@ class SiteAdminConfigurationContent extends React.Component<Props, State> {
         this.setState({ restartToApply })
 
         try {
-            const site = await fetchSite().toPromise()
+            const site = await lastValueFrom(fetchSite())
 
             this.setState({
                 site,
diff --git a/client/web/src/site-admin/UserManagement/components/useUserListActions.tsx b/client/web/src/site-admin/UserManagement/components/useUserListActions.tsx
index 7478f4d1947..be38856c2b0 100644
--- a/client/web/src/site-admin/UserManagement/components/useUserListActions.tsx
+++ b/client/web/src/site-admin/UserManagement/components/useUserListActions.tsx
@@ -1,5 +1,7 @@
 import React, { useState, useCallback } from 'react'
 
+import { lastValueFrom } from 'rxjs'
+
 import { logger } from '@sourcegraph/common'
 import { useMutation } from '@sourcegraph/http-client'
 import { Text } from '@sourcegraph/wildcard'
@@ -202,8 +204,7 @@ export function useUserListActions(onEnd: (error?: any) => void): UseUserListAct
     const handleResetUserPassword = useCallback(
         ([user]: SiteUser[]) => {
             if (confirm('Are you sure you want to reset the selected user password?')) {
-                randomizeUserPassword(user.id)
-                    .toPromise()
+                lastValueFrom(randomizeUserPassword(user.id))
                     .then(({ resetPasswordURL, emailSent }) => {
                         if (resetPasswordURL === null || emailSent) {
                             createOnSuccess(
diff --git a/client/web/src/tour/components/Tour/utils.tsx b/client/web/src/tour/components/Tour/utils.tsx
index 4b729c83711..e2a207535d7 100644
--- a/client/web/src/tour/components/Tour/utils.tsx
+++ b/client/web/src/tour/components/Tour/utils.tsx
@@ -1,6 +1,6 @@
 import isAbsoluteURL from 'is-absolute-url'
 import { memoize, noop } from 'lodash'
-import { type Subscriber, type Subscription, fromEvent, of } from 'rxjs'
+import { type Subscriber, type Subscription, fromEvent, of, lastValueFrom } from 'rxjs'
 import { map } from 'rxjs/operators'
 
 import {
@@ -77,22 +77,22 @@ const firstMatchMessageHandlers: MessageHandlers = {
  */
 const fetchStreamSuggestions = memoize(
     (query: string, sourcegraphURL?: string): Promise<SearchMatch[]> =>
-        search(
-            of(query),
-            {
-                version: LATEST_VERSION,
-                patternType: SearchPatternType.standard,
-                caseSensitive: false,
-                trace: undefined,
-                sourcegraphURL,
-            },
-            firstMatchMessageHandlers
-        )
-            .pipe(
+        lastValueFrom(
+            search(
+                of(query),
+                {
+                    version: LATEST_VERSION,
+                    patternType: SearchPatternType.standard,
+                    caseSensitive: false,
+                    trace: undefined,
+                    sourcegraphURL,
+                },
+                firstMatchMessageHandlers
+            ).pipe(
                 switchAggregateSearchResults,
                 map(suggestions => suggestions.results)
             )
-            .toPromise(),
+        ),
     (query, sourcegraphURL) => `${query}|${sourcegraphURL}`
 )
 
diff --git a/client/web/src/user/settings/auth/RemoveExternalAccountModal.tsx b/client/web/src/user/settings/auth/RemoveExternalAccountModal.tsx
index 3318f5d300b..4988c5d5bdc 100644
--- a/client/web/src/user/settings/auth/RemoveExternalAccountModal.tsx
+++ b/client/web/src/user/settings/auth/RemoveExternalAccountModal.tsx
@@ -1,5 +1,7 @@
 import React, { useCallback, useState } from 'react'
 
+import { lastValueFrom } from 'rxjs'
+
 import { asError, type ErrorLike } from '@sourcegraph/common'
 import { gql, dataOrThrowErrors } from '@sourcegraph/http-client'
 import { Button, Modal, H3, Form } from '@sourcegraph/wildcard'
@@ -9,16 +11,18 @@ import type { Scalars, DeleteExternalAccountResult, DeleteExternalAccountVariabl
 
 const deleteUserExternalAccount = async (externalAccount: Scalars['ID']): Promise<void> => {
     dataOrThrowErrors(
-        await requestGraphQL<DeleteExternalAccountResult, DeleteExternalAccountVariables>(
-            gql`
-                mutation DeleteExternalAccount($externalAccount: ID!) {
-                    deleteExternalAccount(externalAccount: $externalAccount) {
-                        alwaysNil
+        await lastValueFrom(
+            requestGraphQL<DeleteExternalAccountResult, DeleteExternalAccountVariables>(
+                gql`
+                    mutation DeleteExternalAccount($externalAccount: ID!) {
+                        deleteExternalAccount(externalAccount: $externalAccount) {
+                            alwaysNil
+                        }
                     }
-                }
-            `,
-            { externalAccount }
-        ).toPromise()
+                `,
+                { externalAccount }
+            )
+        )
     )
 }
 
diff --git a/client/web/src/user/settings/backend.tsx b/client/web/src/user/settings/backend.tsx
index bfcda808962..1b935541d9d 100644
--- a/client/web/src/user/settings/backend.tsx
+++ b/client/web/src/user/settings/backend.tsx
@@ -1,4 +1,4 @@
-import { EMPTY, type Observable, Subject } from 'rxjs'
+import { EMPTY, type Observable, Subject, lastValueFrom } from 'rxjs'
 import { bufferTime, catchError, concatMap, map } from 'rxjs/operators'
 
 import { createAggregateError } from '@sourcegraph/common'
@@ -126,10 +126,11 @@ export const logEventsMutation = gql`
 `
 
 function sendEvents(events: Event[]): Promise<void> {
-    return requestGraphQL<LogEventsResult, LogEventsVariables>(logEventsMutation, {
-        events,
-    })
-        .toPromise()
+    return lastValueFrom(
+        requestGraphQL<LogEventsResult, LogEventsVariables>(logEventsMutation, {
+            events,
+        })
+    )
         .then(dataOrThrowErrors)
         .then(() => {})
 }
diff --git a/client/web/src/user/settings/emails/AddUserEmailForm.tsx b/client/web/src/user/settings/emails/AddUserEmailForm.tsx
index b6a0627e6ac..55629a6580e 100644
--- a/client/web/src/user/settings/emails/AddUserEmailForm.tsx
+++ b/client/web/src/user/settings/emails/AddUserEmailForm.tsx
@@ -1,6 +1,7 @@
 import React, { type FunctionComponent, useMemo, useState } from 'react'
 
 import classNames from 'classnames'
+import { lastValueFrom } from 'rxjs'
 
 import { asError, isErrorLike, type ErrorLike } from '@sourcegraph/common'
 import { gql, dataOrThrowErrors } from '@sourcegraph/http-client'
@@ -55,16 +56,18 @@ export const AddUserEmailForm: FunctionComponent<React.PropsWithChildren<Props>>
 
             try {
                 dataOrThrowErrors(
-                    await requestGraphQL<AddUserEmailResult, AddUserEmailVariables>(
-                        gql`
-                            mutation AddUserEmail($user: ID!, $email: String!) {
-                                addUserEmail(user: $user, email: $email) {
-                                    alwaysNil
+                    await lastValueFrom(
+                        requestGraphQL<AddUserEmailResult, AddUserEmailVariables>(
+                            gql`
+                                mutation AddUserEmail($user: ID!, $email: String!) {
+                                    addUserEmail(user: $user, email: $email) {
+                                        alwaysNil
+                                    }
                                 }
-                            }
-                        `,
-                        { user: user.id, email: emailState.value }
-                    ).toPromise()
+                            `,
+                            { user: user.id, email: emailState.value }
+                        )
+                    )
                 )
 
                 eventLogger.log('NewUserEmailAddressAdded')
diff --git a/client/web/src/user/settings/emails/SetUserPrimaryEmailForm.tsx b/client/web/src/user/settings/emails/SetUserPrimaryEmailForm.tsx
index f71d501c654..384b1227325 100644
--- a/client/web/src/user/settings/emails/SetUserPrimaryEmailForm.tsx
+++ b/client/web/src/user/settings/emails/SetUserPrimaryEmailForm.tsx
@@ -1,6 +1,7 @@
 import React, { useState, type FunctionComponent, useCallback } from 'react'
 
 import classNames from 'classnames'
+import { lastValueFrom } from 'rxjs'
 
 import { asError, type ErrorLike, isErrorLike } from '@sourcegraph/common'
 import { gql, dataOrThrowErrors } from '@sourcegraph/http-client'
@@ -58,16 +59,18 @@ export const SetUserPrimaryEmailForm: FunctionComponent<React.PropsWithChildren<
 
             try {
                 dataOrThrowErrors(
-                    await requestGraphQL<SetUserEmailPrimaryResult, SetUserEmailPrimaryVariables>(
-                        gql`
-                            mutation SetUserEmailPrimary($user: ID!, $email: String!) {
-                                setUserEmailPrimary(user: $user, email: $email) {
-                                    alwaysNil
+                    await lastValueFrom(
+                        requestGraphQL<SetUserEmailPrimaryResult, SetUserEmailPrimaryVariables>(
+                            gql`
+                                mutation SetUserEmailPrimary($user: ID!, $email: String!) {
+                                    setUserEmailPrimary(user: $user, email: $email) {
+                                        alwaysNil
+                                    }
                                 }
-                            }
-                        `,
-                        { user: user.id, email: primaryEmail }
-                    ).toPromise()
+                            `,
+                            { user: user.id, email: primaryEmail }
+                        )
+                    )
                 )
 
                 eventLogger.log('UserEmailAddressSetAsPrimary')
diff --git a/client/web/src/user/settings/emails/UserEmail.tsx b/client/web/src/user/settings/emails/UserEmail.tsx
index 83693122be8..c4ba19161e9 100644
--- a/client/web/src/user/settings/emails/UserEmail.tsx
+++ b/client/web/src/user/settings/emails/UserEmail.tsx
@@ -1,5 +1,7 @@
 import { type FunctionComponent, useState, useCallback } from 'react'
 
+import { lastValueFrom } from 'rxjs'
+
 import { asError, type ErrorLike } from '@sourcegraph/common'
 import { dataOrThrowErrors, gql } from '@sourcegraph/http-client'
 import { Badge, Button, screenReaderAnnounce } from '@sourcegraph/wildcard'
@@ -35,16 +37,18 @@ export const resendVerificationEmail = async (
 ): Promise<void> => {
     try {
         dataOrThrowErrors(
-            await requestGraphQL<ResendVerificationEmailResult, ResendVerificationEmailVariables>(
-                gql`
-                    mutation ResendVerificationEmail($userID: ID!, $email: String!) {
-                        resendVerificationEmail(user: $userID, email: $email) {
-                            alwaysNil
+            await lastValueFrom(
+                requestGraphQL<ResendVerificationEmailResult, ResendVerificationEmailVariables>(
+                    gql`
+                        mutation ResendVerificationEmail($userID: ID!, $email: String!) {
+                            resendVerificationEmail(user: $userID, email: $email) {
+                                alwaysNil
+                            }
                         }
-                    }
-                `,
-                { userID, email }
-            ).toPromise()
+                    `,
+                    { userID, email }
+                )
+            )
         )
 
         eventLogger.log('UserEmailAddressVerificationResent')
@@ -79,16 +83,18 @@ export const UserEmail: FunctionComponent<React.PropsWithChildren<Props>> = ({
 
         try {
             dataOrThrowErrors(
-                await requestGraphQL<RemoveUserEmailResult, RemoveUserEmailVariables>(
-                    gql`
-                        mutation RemoveUserEmail($user: ID!, $email: String!) {
-                            removeUserEmail(user: $user, email: $email) {
-                                alwaysNil
+                await lastValueFrom(
+                    requestGraphQL<RemoveUserEmailResult, RemoveUserEmailVariables>(
+                        gql`
+                            mutation RemoveUserEmail($user: ID!, $email: String!) {
+                                removeUserEmail(user: $user, email: $email) {
+                                    alwaysNil
+                                }
                             }
-                        }
-                    `,
-                    { user, email }
-                ).toPromise()
+                        `,
+                        { user, email }
+                    )
+                )
             )
 
             setIsLoading(false)
@@ -108,16 +114,18 @@ export const UserEmail: FunctionComponent<React.PropsWithChildren<Props>> = ({
 
         try {
             dataOrThrowErrors(
-                await requestGraphQL<SetUserEmailVerifiedResult, SetUserEmailVerifiedVariables>(
-                    gql`
-                        mutation SetUserEmailVerified($user: ID!, $email: String!, $verified: Boolean!) {
-                            setUserEmailVerified(user: $user, email: $email, verified: $verified) {
-                                alwaysNil
+                await lastValueFrom(
+                    requestGraphQL<SetUserEmailVerifiedResult, SetUserEmailVerifiedVariables>(
+                        gql`
+                            mutation SetUserEmailVerified($user: ID!, $email: String!, $verified: Boolean!) {
+                                setUserEmailVerified(user: $user, email: $email, verified: $verified) {
+                                    alwaysNil
+                                }
                             }
-                        }
-                    `,
-                    { user, email, verified }
-                ).toPromise()
+                        `,
+                        { user, email, verified }
+                    )
+                )
             )
 
             setIsLoading(false)
diff --git a/client/web/src/user/settings/emails/UserSettingsEmailsPage.tsx b/client/web/src/user/settings/emails/UserSettingsEmailsPage.tsx
index 2655be2fc5c..879ff7943be 100644
--- a/client/web/src/user/settings/emails/UserSettingsEmailsPage.tsx
+++ b/client/web/src/user/settings/emails/UserSettingsEmailsPage.tsx
@@ -1,6 +1,7 @@
 import React, { type FunctionComponent, useEffect, useState, useCallback } from 'react'
 
 import classNames from 'classnames'
+import { lastValueFrom } from 'rxjs'
 
 import { asError, type ErrorLike, isErrorLike } from '@sourcegraph/common'
 import { gql, dataOrThrowErrors, useQuery } from '@sourcegraph/http-client'
@@ -142,27 +143,29 @@ export const UserSettingsEmailsPage: FunctionComponent<React.PropsWithChildren<P
 
 async function fetchUserEmails(userID: Scalars['ID']): Promise<UserEmailsResult> {
     return dataOrThrowErrors(
-        await requestGraphQL<UserEmailsResult, UserEmailsVariables>(
-            gql`
-                fragment UserEmail on UserEmail {
-                    email
-                    isPrimary
-                    verified
-                    verificationPending
-                    viewerCanManuallyVerify
-                }
-                query UserEmails($user: ID!) {
-                    node(id: $user) {
-                        ... on User {
-                            __typename
-                            emails {
-                                ...UserEmail
+        await lastValueFrom(
+            requestGraphQL<UserEmailsResult, UserEmailsVariables>(
+                gql`
+                    fragment UserEmail on UserEmail {
+                        email
+                        isPrimary
+                        verified
+                        verificationPending
+                        viewerCanManuallyVerify
+                    }
+                    query UserEmails($user: ID!) {
+                        node(id: $user) {
+                            ... on User {
+                                __typename
+                                emails {
+                                    ...UserEmail
+                                }
                             }
                         }
                     }
-                }
-            `,
-            { user: userID }
-        ).toPromise()
+                `,
+                { user: userID }
+            )
+        )
     )
 }
diff --git a/package.json b/package.json
index 07d26f7b317..ba3039986b9 100644
--- a/package.json
+++ b/package.json
@@ -396,7 +396,7 @@
     "recharts": "^1.8.5",
     "regexpp": "^3.1.0",
     "resize-observer-polyfill": "^1.5.1",
-    "rxjs": "^6.6.3",
+    "rxjs": "^7.8.1",
     "semver": "^7.3.2",
     "stream-http": "^3.2.0",
     "stream-json": "^1.7.5",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 87cf53d056b..465f4d980c7 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -407,8 +407,8 @@ importers:
         specifier: ^1.5.1
         version: 1.5.1
       rxjs:
-        specifier: ^6.6.3
-        version: 6.6.7
+        specifier: ^7.8.1
+        version: 7.8.1
       semver:
         specifier: ^7.3.2
         version: 7.6.0
@@ -22898,6 +22898,7 @@ packages:
     engines: {npm: '>=2.0.0'}
     dependencies:
       tslib: 2.1.0
+    dev: true
 
   /rxjs@7.8.1:
     resolution: {integrity: sha512-AA3TVj+0A2iuIoQkWEK/tqFjBq2j+6PO6Y0zJcvzLAFhEFIO3HL0vls9hWLncZbAAbK0mar7oZ4V079I/qPMxg==}