What is ngZone, and how does it relate to Angular’s change detection?

Short answer: Angular uses NgZone to detect asynchronous events (like clicks, timers, HTTP). NgZone runs code inside Angular's zone, triggering change detection automatically. You can run code outside Angular's zone to prevent unnecessary change detection. ✅

Example code

constructor(private ngZone: NgZone) {} runHeavyTaskOutsideAngular() { this.ngZone.runOutsideAngular(() => { // code here won't trigger change detection }); }

Real-world example (ShopNest)

ShopNest admin can be built in Angular with modules/components, services for API calls, and reactive forms for product edit.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.