Angular Typescript Interview Question Answers Part 4
Angular Interview Questions – Part 4 (Expert / Modern Angular)
61. What are Signals in Angular?
Answer: Signals are a new reactive state mechanism introduced to simplify state management.
Why Signals:
- Fine-grained reactivity
- Faster than traditional change detection
- Less RxJS boilerplate
Use case: Local component state (counters, UI state).
62. Signals vs Observables
Answer:
| Signals | Observables |
|---|---|
| Sync by default | Async |
| Simple state | Streams of data |
| Automatic tracking | Manual subscriptions |
Interview tip: Signals don’t replace RxJS, they complement it.
63. What is Angular Control Flow Syntax?
Answer: New Angular syntax replacing structural directives.
Examples:
@if@for@switch
Benefits:
- Better performance
- Cleaner templates
- Type-safe
64. What are Deferrable Views?
Answer: Deferrable views load parts of UI only when needed.
Why important:
- Faster initial load
- Reduced bundle size
Example use case: Load charts only when user scrolls.
65. What is Angular Standalone Routing?
Answer:
Routing without NgModule.
Benefits:
- Less boilerplate
- Modern Angular architecture
- Easier lazy loading
66. What is Angular Testing?
Answer: Angular provides tools to test:
- Components
- Services
- Pipes
- Guards
Testing types:
- Unit testing
- Integration testing
- E2E testing
67. Jasmine vs Karma
Answer:
| Jasmine | Karma |
|---|---|
| Testing framework | Test runner |
| Writes test cases | Runs tests in browser |
Together: Used for Angular unit testing.
68. What is TestBed?
Answer:
TestBed configures Angular testing environment.
Used for:
- Creating test modules
- Injecting services
- Testing components
69. What is Mocking in Angular Tests?
Answer: Mocking replaces real dependencies with fake ones.
Why needed:
- Faster tests
- Isolation
- Predictable results
70. What is E2E Testing?
Answer: End-to-End testing checks full application flow.
Tools:
- Cypress
- Playwright
Example: Login → Dashboard → Logout.
71. What is Angular Internationalization (i18n)?
Answer: i18n allows app to support multiple languages.
Use case: Global applications.
72. What is Angular PWA?
Answer: Progressive Web App enables:
- Offline access
- App-like experience
- Push notifications
Key feature: Service Workers.
73. What is Service Worker in Angular?
Answer: Runs in background and handles:
- Caching
- Offline support
- Push notifications
74. What is Tree Shaking?
Answer: Removes unused code during build.
Benefit: Smaller bundle size → faster load.
75. What is Builder in Angular?
Answer: Builders define how Angular builds, tests, or serves the app.
Examples:
- Build
- Serve
- Test
76. What is Custom Webpack in Angular?
Answer: Allows extending default Angular build process.
Use case: Special loaders, plugins.
77. How does Angular handle Large-Scale Architecture?
Answer:
- Lazy-loaded modules
- Shared libraries
- Micro frontends
- State management (NgRx)
78. What is Nx in Angular Ecosystem?
Answer: Nx is a tool for monorepo management.
Benefits:
- Code sharing
- Faster builds
- Better scaling
79. Real Production Scenario Question
Question: Angular app performance degrades over time. What will you check?
Answer:
- Memory leaks
- Unsubscribed observables
- Change detection strategy
- Heavy pipes
- Bundle size
80. Lead-Level Interview Question
Question: How do you design a scalable Angular app?
Answer:
- Standalone components
- Lazy loading
- OnPush strategy
- Clear folder structure
- Strong state management