Angular runs change detection after every async event (clicks, timeouts, XHR). But what if you want to manually control it?
When an interviewer asks about performance, introduce NgZone immediately.
You understand the microsyntax ( * ) desugars to <ng-template> . You understand ViewContainerRef handles the DOM. This is senior-level. 6. The "Hydration" Question – Angular 17+ & SSR Pitfalls With Angular 17+, Server-Side Rendering (SSR) and Hydration are defaults. Interviewers are now asking about hydration mismatches.
// This component will NOT look up the parent tree. // If it doesn't have its own, it throws null (not a parent one). constructor(@Self() @Optional() public config: AppConfigService) {} In Angular 15+, providedIn: 'root' is lazy-loaded, but if you use providedIn: 'platform' , your service survives app re-initialization. Perfect for auth services. 3. Reactive Hacks: Signals vs. RxJS – The Interviewer’s Dilemma This is the hottest topic in 2024/2025. Angular is moving to Signals.
In the modern JavaScript ecosystem, Angular interviews have shifted. They no longer test documentation memory. They test , Reactive performance , and Dependency Injection magic .
<!-- If server says "0" but client says "1" -> Mismatch Error --> <!-- Hack: Skip hydration for dynamic parts --> <div ngSkipHydration> dynamicComponentThatUsesWindow.innerWidth </div> When using TransferState to pass data from server to client to avoid re-fetching data.
// Server: Set data transferState.set<T>(MY_KEY, data); // Client: Check if exists before HTTP call const saved = transferState.get(MY_KEY, null); if (saved) // Use saved data AND remove it to save memory transferState.remove(MY_KEY);
"Will RxJS die?"
