Angular Performance Optimization Techniques

Performance is crucial for user experience. Here are proven techniques to optimize your Angular applications.

1. Lazy Loading

Implement lazy loading for feature modules to reduce initial bundle size:

const routes: Routes = [
  {
    path: 'admin',
    loadChildren: () => import('./admin/admin.module').then(m => m.AdminModule)
  }
];

2. OnPush Change Detection

Use OnPush change detection strategy to reduce unnecessary checks:

@Component({
  selector: 'app-user-list',
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: '...'
})
export class UserListComponent {}

3. TrackBy Functions

Always use trackBy with *ngFor to help Angular identify which items have changed:

trackByUserId(index: number, user: User): number {
  return user.id;
}

4. Unsubscribe from Observables

Prevent memory leaks by unsubscribing from observables:

private destroy$ = new Subject();

ngOnInit() {
  this.dataService.getData()
    .pipe(takeUntil(this.destroy$))
    .subscribe(data => this.data = data);
}

ngOnDestroy() {
  this.destroy$.next();
  this.destroy$.complete();
}

These techniques will significantly improve your Angular application's performance and user experience.