API Design and Data Fetching Strategies Questions

End to end design and client side integration of data APIs and fetching strategies. On the server side consider representational state transfer design principles, GraphQL schema and query trade offs, endpoint versioning, pagination approaches, batching, idempotency, and error semantics. On the client side cover pagination and incremental loading, request cancellation and abort semantics, debouncing and throttling, retry strategies and exponential backoff, optimistic updates, loading and error state management, and client side caching patterns such as stale while revalidate. Also include real time synchronization options such as WebSockets and server sent events, offline first synchronization and conflict resolution, service worker integration, and security considerations for authentication and authorization.