Angular work skews toward large, long-lived enterprise codebases, so these questions probe architecture judgment and RxJS discipline rather than syntax recall. Each one includes what a strong answer should cover, so you can grade responses even if Angular is not your own specialty.
What a strong answer covers
They should describe Zone.js triggering checks from the root down, OnPush as the standard mitigation, and why immutable inputs make OnPush safe. Strong candidates mention signals as the newer fine-grained alternative and can name a real case where they profiled and fixed a detection storm.
What a strong answer covers
Signals for synchronous local and derived state, observables for genuinely asynchronous streams like HTTP, websockets, and debounced input. A good answer shows they follow Angular's direction of travel without dogma and can describe interop such as toSignal and toObservable at the boundary.
What a strong answer covers
Root, route/lazy-module or environment injectors, and component-level providers, with the consequence each has for instance sharing and memory. Listen for providedIn: 'root' as the default, and component-level provision reserved for deliberately scoped state such as per-widget stores.
What a strong answer covers
The async pipe as the first choice because it unsubscribes automatically, then takeUntilDestroyed or DestroyRef for imperative cases. Candidates who only offer manual unsubscribe in ngOnDestroy are behind; ones who mention leak symptoms they have actually debugged are ahead.
What a strong answer covers
This is the classic RxJS judgment test. Expect switchMap for typeahead search (cancel stale requests), concatMap for ordered writes, mergeMap for independent parallel work, and exhaustMap for ignoring repeat clicks on a submit button. Mapping each to a UI scenario matters more than definitions.
What a strong answer covers
Standalone components or feature modules with clear public APIs, lazy-loaded route boundaries, a shared library layer, and possibly an Nx-style monorepo with enforced dependency rules. The best answers talk about ownership boundaries and build times, not just folder names.
What a strong answer covers
Separate bundles fetched on first navigation to the route, smaller initial payload, and faster first paint. Verification via the network tab or a bundle analyzer, plus route-level code splitting configuration. Preloading strategies are a nice extra signal.
What a strong answer covers
Reactive forms for anything non-trivial: testability, dynamic validation, typed forms. A custom control means implementing ControlValueAccessor; candidates should be able to sketch writeValue and the onChange registration. Mentioning typed forms shows current knowledge.
What a strong answer covers
A systematic story: check whether the component is reused by the router rather than recreated, inspect route param subscriptions, look at caching in services or interceptors, and confirm change detection strategy. You are grading the debugging method as much as the answer.
What a strong answer covers
A chain that wraps every HttpClient request. Real-world uses: attaching auth tokens, refresh-token flows, global error handling, retry with backoff, and logging. Strong candidates note ordering effects when several interceptors are registered.
What a strong answer covers
Services and pure logic under plain unit tests, components through TestBed or a component-harness style, and a thin end-to-end layer with Playwright or Cypress. Listen for opinions on avoiding brittle DOM assertions and on testing observables with marble or firstValueFrom patterns.
What a strong answer covers
Incremental hops using ng update version by version, reading the update guide, fixing deprecations before each hop, and keeping the app releasable throughout. Anyone proposing a big-bang rewrite to the latest version without discussing risk is waving a flag.
What a strong answer covers
Angular SSR with hydration, the SEO and first-paint motivation, and honest discussion of the operational cost: a Node server, careful use of browser-only APIs, and state transfer to avoid double-fetching. Worth it for public content-heavy pages, rarely for internal tools.
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Try the interview question generator →Five to seven, chosen to match the role. Pick two fundamentals, two RxJS or state questions, and two architecture questions for senior candidates, then leave room for follow-ups — depth on fewer questions beats coverage of many.
Yes — that is what the listen-for notes are for. Score whether the candidate hits the marked points and explains trade-offs in plain language. A genuinely senior engineer can make change detection understandable to a non-specialist.
Seniors reason about consequences: bundle size, change-detection cost, team boundaries, and upgrade paths. Mid-level candidates describe the mechanism correctly; seniors tell you when they would not use it.
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