Mid-level candidates know how to make things work. Senior candidates proactively discuss performance implications before they're asked.

: Instructs Angular to look for the dependency only in the local element injector.

Interviewers love to test a candidate's understanding of how Angular updates the DOM. The curriculum breaks down:

Angular and RxJS are inseparable. If you want to ace the frontend interview, you must be able to "decode" complex observable streams.

Failing to unsubscribe from custom observables creates severe memory leaks. Be ready to explain how to prevent this using lifecycle hooks or declarations:

Runs all inner observables concurrently. Ideal for independent save operations.

This layered approach is precisely what the Decoded Frontend "Interview Hacking" course emphasizes, with each topic tiered from Junior to Senior levels.

Unsubscribed observables cause severe memory leaks. Always leverage these safe patterns:

Asynchronous reactive programming is a common stumbling block in technical assessments. The training focuses on:

The by Decoded Frontend is a premium technical preparation program designed to help developers ace front-end engineering interviews. Created by Dmytro Mezhenskyi , a Google Developer Expert (GDE) in Angular and Microsoft MVP, this course bridges the gap between basic framework knowledge and the advanced systems-level understanding expected by top-tier tech companies.

: Scope a service instance specifically to a component and its children.

However, Zone.js comes with performance costs—it triggers change detection more often than necessary. (available in Angular 20+) removes Zone.js entirely, relying on Signals and manual triggers instead. Senior candidates should explain:

They’ll ask: "Can you override a service for a specific component?" Nail it with: "Use providers: [CustomService] at component level or @Injectable( providedIn: 'root' ) with factory providers."