Redux Toolkit’s RTK Query is the most powerful data fetching and caching solution for Redux applications, automating loading states, error handling, and cache invalidation that you’d otherwise write by hand. As the creator of CoreUI with 25 years of front-end development experience, I use RTK Query in complex React dashboards where multiple components fetch the same data and need to stay synchronized without redundant API calls. Define your API once with createApi, and RTK Query generates typed hooks, manages caching, handles request deduplication, and automatically re-fetches stale data. This eliminates the need to write fetchUsers.pending, fetchUsers.fulfilled, and fetchUsers.rejected reducers for every endpoint.