#performance

shareReplay: Caching HTTP Requests and Killing Duplicate Calls in Angular

Cold vs hot observables, shareReplay({ bufferSize: 1, refCount: true }) actually caching a request, and a real gotcha with refCount that only shows up with sources that never complete on their own.

What NgRx Actually Is, and the Change Detection Problem It Quietly Solves

Zone.js, change detection, and OnPush explain why NgRx exists: the pillars (actions, reducers, selectors, effects), how far back it goes, and how DevTools turns debugging state into a timeline.