We can divide angular optimizations into 2 groups:

• Network optimizations: improve mostly the load time (latency / bandwidth)
• Runtime optimizations: improve runtime performance (change detection / rendering)

Network optimizations

1. Lazy loading (router)

2. Minification / Dead Code Elimination

3. Compression (gzip / brotli)

Resources:

• "Building an Angular Application for Production": blog.mgechev.com/2016/06/26/tree-shaking-angular2-production-build-rollup-javascript/
• "2.5X Smaller Angular Applications with Google Closure Compiler": blog.mgechev.com/2016/07/21/even-smaller-angular2-applications-closure-tree-shaking/
• hacks.mozilla.org/2015/11/better-than-gzip-compression-with-brotli/

4. AOT compilation

5. Pre-fetching Resources (preload, prefetch, preconnect, dns-prefetch, prerender)

• preload: download and cash asap (for resources now)
• prefetch: download and cash on idle (for next page resources)
• dns-prefetch: resolve dns before
• preconnect: connect to domain before
• prerender: asks browser load url address and prerender it on "invisible tab" (you know that user will go to this page)

6. Caching

7. Service Workers

Resources:

• Angular Service Worker (angular.io/guide/service-worker-intro) — Aims to automate the process of managing Service Workers. It also contains Service Worker for caching static assets and one for generating application shell: developers.google.com/web/updates/2015/11/app-shell?hl=en.

Runtime optimizations

1. OnPush CD + Immutable

2. Smart + Dumb components

3. Pure pipes instead of method calls in templates

4. Pure pipes with caching (@memo)

5. *ngFor with trackBy

6. Async pipes

7. Detaching CD

8. Informative configurations: linting, bundle size budgets

9. Use enableProdMode

10. WebWorkers

11. SSR

12. Unsubscribe logic (takeUntil)

13. providedIn

Resources

• https://github.com/mgechev/angular-performance-checklist
• https://www.youtube.com/watch?v=WdSXDGtd9lY&ab_channel=AngularMeetupZurich
• (takeUntil) https://stackoverflow.com/questions/57007118/do-i-need-to-complete-takeuntil-subject-inside-ngondestroy
• (takeUntil) https://cartant.medium.com/rxjs-avoiding-takeuntil-leaks-fb5182d047ef