@@ -12,6 +12,7 @@ import { createRequire } from 'node:module';
 import { MessageChannel } from 'node:worker_threads';
 import type { SourceFile } from 'typescript';
 import { WorkerPool } from '../../../utils/worker-pool';
+import { mergeCumulativeDurations } from '../../esbuild/profiling';
 import type { AngularHostOptions } from '../angular-host';
 import { AngularCompilation, DiagnosticModes, EmitFileResult } from './angular-compilation';
 
@@ -124,10 +125,15 @@ export class ParallelCompilation extends AngularCompilation {
     throw new Error('Not implemented in ParallelCompilation.');
   }
 
-  override diagnoseFiles(
+  override async diagnoseFiles(
     modes = DiagnosticModes.All,
   ): Promise<{ errors?: PartialMessage[]; warnings?: PartialMessage[] }> {
-    return this.#worker.run(modes, { name: 'diagnose' });
+    const { timings, ...result } = await this.#worker.run(modes, { name: 'diagnose' });
+    if (timings) {
+      mergeCumulativeDurations(timings);
+    }
+
+    return result;
   }
 
   override emitAffectedFiles(): Promise<Iterable<EmitFileResult>> {
 
@@ -11,6 +11,7 @@ import assert from 'node:assert';
 import { randomUUID } from 'node:crypto';
 import { type MessagePort, receiveMessageOnPort } from 'node:worker_threads';
 import { SourceFileCache } from '../../esbuild/angular/source-file-cache';
+import { getAndClearCumulativeDurations } from '../../esbuild/profiling';
 import type { AngularCompilation, DiagnosticModes } from './angular-compilation';
 import { AotCompilation } from './aot-compilation';
 import { JitCompilation } from './jit-compilation';
@@ -121,12 +122,17 @@ export async function initialize(request: InitRequest) {
 export async function diagnose(modes: DiagnosticModes): Promise<{
   errors?: PartialMessage[];
   warnings?: PartialMessage[];
+  timings?: Record<string, number[]>;
 }> {
   assert(compilation);
 
   const diagnostics = await compilation.diagnoseFiles(modes);
+  const timings = getAndClearCumulativeDurations();
 
-  return diagnostics;
+  return {
+    ...diagnostics,
+    timings,
+  };
 }
 
 export async function emit() {
 
@@ -14,6 +14,32 @@ export function resetCumulativeDurations(): void {
   cumulativeDurations?.clear();
 }
 
+export function getAndClearCumulativeDurations(): Record<string, number[]> | undefined {
+  if (!cumulativeDurations || cumulativeDurations.size === 0) {
+    return undefined;
+  }
+
+  const data = Object.fromEntries(cumulativeDurations);
+
+  cumulativeDurations.clear();
+
+  return data;
+}
+
+export function mergeCumulativeDurations(data: Record<string, number[]>): void {
+  cumulativeDurations ??= new Map();
+
+  for (const [name, durations] of Object.entries(data)) {
+    let existing = cumulativeDurations.get(name);
+    if (!existing) {
+      existing = [];
+      cumulativeDurations.set(name, existing);
+    }
+
+    existing.push(...durations);
+  }
+}
+
 export function logCumulativeDurations(): void {
   if (!debugPerformance || !cumulativeDurations) {
     return;