Angular apps can stay fast for a long time, until they don't. A lot of performance issues i've debugged had nothing to do with bundle size or server speed. The real problem was change detection doing way more work than it needed.
Here are some common mistakes.
1. Using the default strategy everywhere
Angular's default change detection is convenient, but it checks more often than many apps actually need. For bigger applications, this can become expensive fast. Using OnPush in the right places can reduce unnecessary updates a lot.
2. Calling functions directly in templates
