Redux & Redux Toolkit Course
Redux & Redux Toolkit
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Advanced

Scalable Redux Applications

Definition

Architecting Redux so that an app can grow to hundreds of thousands of lines of code without becoming a tangled, unmaintainable mess.

Explain Like I'm New

If 50 developers are working on the same app, you need strict rules. Rules like: Don't put form state in Redux. Use RTK Query for all API calls. Normalize data. Use TypeScript. Use Memoized Selectors for everything.

Real World Example

Twitter/X using Redux to manage the main feed, notifications, and DMs seamlessly without the UI freezing when a new tweet arrives.

Common Use Cases

  • •Enterprise software architecture

Terminal Output

bash / terminal
/* Checklist for a Scalable Redux App: [x] Are we using Redux Toolkit exclusively? (No legacy Redux) [x] Are we using RTK Query for data fetching instead of manual Thunks? [x] Is our state Normalized (flat) instead of deeply nested arrays? [x] Are we using useAppSelector (Typed Hooks) instead of useSelector? [x] Is Local state used for forms/modals, reserving Redux for Global data? */

Interview Questions

basic

  • Is it a good idea to store the UI state of every single dropdown menu and modal in Redux to ensure the app is highly scalable?

intermediate

  • How does strict TypeScript typing aid in Redux scalability?

Flash Cards

Question

Store every UI state in Redux?

Click to reveal answer
Answer

NO! That is a massive anti-pattern. Global state should be kept as small as possible. Local UI state belongs in React `useState`.

Question

How does TS aid scalability?

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Answer

When an app is massive, developers cannot memorize the shape of the State Tree. TypeScript provides autocomplete and catches errors instantly if a developer tries to select `state.user.firstname` instead of `state.user.firstName`.