Redux Toolkit Best Practices for Scalable React Apps

Redux Toolkit Best Practices for Scalable React Apps

Redux Toolkit is powerful, but using it well in a scalable app requires discipline. Here are the best practices.

Organize Slices by Feature

Group state and reducers by feature, not by file type. A cart slice holds all cart state and logic. This keeps related code together and easy to find.

Select Only What You Need

In useSelector, select the specific data a component needs, not a whole slice. This prevents unnecessary re-renders when unrelated parts of the slice change.

Use createAsyncThunk for Async

Handle data fetching and other async logic with createAsyncThunk, and manage pending, fulfilled, and rejected in extraReducers. Do not hand-roll async in reducers.

Keep Reducers Pure

Reducers must be pure functions with no side effects. RTK's Immer lets you write mutating-looking code safely, but never put side effects like API calls in a reducer.

Use RTK Query for Data Fetching

For API data, consider RTK Query, which handles caching, invalidation, and loading states for you. It removes most hand-written data-fetching code.

Normalize Complex Data

For lists of entities that are often updated, normalize the data into a dictionary keyed by id. RTK's createEntityAdapter helps with this.

Keep UI State Local

Not everything belongs in Redux. Local UI state like a modal open flag should stay in component state. Redux is for shared, complex state.

The Takeaway

Organize slices by feature, select only what you need, use createAsyncThunk for async, keep reducers pure, consider RTK Query for API data, normalize complex entities, and keep UI state local. These keep Redux scalable.