Angular has evolved into one of the most powerful front-end frameworks for building modern, scalable, and enterprise-level applications. For developers of experienced, interviews not only test your **theoretical knowledge** but also your **hands-on expertise** in building, deploying, and maintaining real-world Angular applications.
In this article, we’ll walk through the **key areas in Angular** you should master — starting from fundamentals to advanced production-ready concepts.
## 1. Angular Lifecycle Hooks
Lifecycle hooks are crucial for managing component creation, rendering, and destruction. Be prepared to explain **when and why** to use them.
* **ngOnInit**: Initialize component data.
* **ngOnChanges**: Detect changes in input-bound properties.
* **ngDoCheck**: Custom change detection.
* **ngAfterViewInit & ngAfterContentInit**: DOM and content initialization.
* **ngOnDestroy**: Cleanup, unsubscribe from Observables, release resources.
👉 **Interview Tip**: Be ready with real-time scenarios like unsubscribing in `ngOnDestroy` to prevent memory leaks.
## 2. Routing & Navigation
Routing is the backbone of any Angular application. Understand:
* **RouterModule** setup with `forRoot()` and `forChild()`.
* **Lazy Loading** modules for performance optimization.
* **Child Routes & Wildcards** (`**` for 404 pages).
* **Route Guards** (AuthGuard, CanActivate, CanDeactivate, Resolve).
* **Preloading strategies** for balancing lazy loading with speed.
👉 Example: Use `AuthGuard` with JWT tokens to restrict access to secure routes.
## 3. Forms in Angular
Forms are everywhere in enterprise apps. You must be comfortable with both approaches:
* **Template-driven forms** (simple, quick setup, two-way binding).
* **Reactive forms** (more control, validation, and scalability).
Key concepts:
* FormControl, FormGroup, FormBuilder.
* Built-in and custom validators.
* Async validators (e.g., checking if a username already exists).
* Dynamic form generation.
## 4. Angular Material & UI Components
Angular Material provides ready-to-use UI components. Focus on:
* Data tables with sorting, pagination, filtering.
* Dialogs, snackbars, and modals.
* Responsive layouts using Flex Layout/Grid.
* Theming and customization.
👉 **Interview Tip**: Be able to explain how Angular Material improves productivity and consistency.
## 5. Dependency Injection (DI)
Angular’s DI system is core to writing maintainable code. Know:
* Provider scopes: root, feature module, component.
* Hierarchical injectors.
* `@Injectable({ providedIn: 'root' })` usage.
* Tree-shakable providers.
* Use cases of `InjectionToken`.
## 6. HTTP Interceptors & API Handling
Interceptors allow you to **modify requests/responses globally**. Key scenarios:
* Attaching **JWT tokens** to headers.
* Global error handling (e.g., redirect to login on `401 Unauthorized`).
* Request/response logging.
* Caching responses for performance.
## 7. Authentication & Authorization (JWT Implementation)
Almost every production app requires authentication. Learn how to:
* Store and manage JWT tokens securely (localStorage vs cookies).
* Refresh tokens.
* Use interceptors to attach tokens.
* Protect routes with AuthGuards.
* Role-based access control.
👉 **Hands-on Task**: Implement login/logout with JWT, refresh tokens, and secure route navigation.
## 8. Caching & Performance Optimization
Production-grade apps demand speed. Interviewers expect knowledge of:
* Browser caching strategies (LocalStorage, IndexedDB).
* API response caching via interceptors.
* `OnPush` change detection strategy.
* Lazy loading and preloading strategies.
* TrackBy with `*ngFor` to prevent re-rendering.
## 9. Server-Side Rendering (SSR) with Angular Universal
For SEO and performance, Angular Universal is important. Be ready to answer:
* How SSR improves **SEO** for Angular apps.
* Setting up Angular Universal.
* Handling API calls on the server vs client.
* Differences between CSR (Client-Side Rendering) and SSR.
## 10. Error Handling & Logging
Enterprise apps need solid error handling. Know how to:
* Use **ErrorHandler** class for global error handling.
* Implement custom error services.
* Log errors to monitoring tools (e.g., Sentry, Azure App Insights).
* Show user-friendly error messages.
## 11. State Management (NgRx / Services)
Large apps often use state management. You should:
* Understand RxJS and Observables deeply.
* Be able to explain state management with Services and BehaviorSubject.
* Know NgRx basics: Actions, Reducers, Effects, Store.
* When to choose NgRx vs simple service-based state management.
## 12. Production-Level Deployment
Finally, demonstrate deployment expertise:
* `ng build --prod` optimizations (AOT compilation, minification, tree-shaking).
* Hosting on **Azure, AWS, Firebase, or Nginx**.
* Environment configuration (`environment.ts`).
* CI/CD pipeline setup for Angular apps.
* Handling SSL, security headers, and API proxy configuration.
## Conclusion
For a experienced Angular developer, interviews focus less on syntax and more on **architecture, scalability, performance, and deployment**.
If you cover these areas thoroughly — from lifecycle hooks, routing, forms, interceptors, JWT, Angular Universal, to production deployment — you’ll not only crack interviews but also be confident in building enterprise-grade Angular applications.
✅ **Pro Tip**: Build a small end-to-end Angular project that includes authentication, lazy loading, caching, Angular Material UI, and SSR. This will help you confidently explain your real-world experience.
