This question is massive and they absolutely know it.
Start by comparing Redux with modern alternatives like React Query, Zustand, and Context API, focusing on trade-offs in complexity, caching, and server-state management. Then design a layered architecture that separates server state (React Query) from client state (Zustand/Redux), and detail how to handle offline, pagination, optimistic updates, and retries using appropriate tools and patterns.
Pro tip: Emphasize that Redux is not obsolete but should be reserved for complex client state, while server state is better managed by specialized libraries like React Query. Mention DoorDash's scale and need for reliability to justify choices like IndexedDB for offline and exponential backoff for retries.
Discuss Redux's strengths (predictable state, dev tools, middleware) and weaknesses (boilerplate, overkill for server state). Contrast with React Query (server state, caching, retries), Zustand (lightweight client state), and Context (simple, but not for frequent updates).
Propose a hybrid approach: use React Query for server state (API data, caching, pagination, retries) and a lightweight client state manager like Zustand or Redux Toolkit for global UI state (e.g., cart, modals).
Outline offline support using service workers for caching assets and IndexedDB (via localForage or Dexie) for storing API responses. Use React Query's persistence plugin to hydrate cache on load.
For pagination, use React Query's infinite queries or cursor-based pagination. For optimistic updates, use React Query's onMutate to update cache immediately, with rollback on error.
Configure retries with exponential backoff in React Query. For offline mutations, queue them in IndexedDB and replay when online, using a library like react-query-offline or custom logic.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.