Data Fetching Interview Questions

Next.js 13+ provides async Server Components, fetch() with caching options, server actions, and client-side fetching methods. Supports static and dynamic data fetching with options for revalidation.

Use async/await directly in Server Components. Example: async function Page() { const data = await fetch('api/data'); return <Component data={data} />}. Supports automatic caching and revalidation.

Static data fetching occurs at build time using fetch with cache: 'force-cache' option. Data is cached and reused across requests. Suitable for content that doesn't change frequently.

Use fetch with cache: 'no-store' option or revalidate: 0 for dynamic data. Data fetched on every request. Suitable for real-time or frequently changing data.

ISR allows static pages to be updated after build time. Use fetch with revalidate option. Combines benefits of static and dynamic rendering. Pages regenerated based on time interval.

Use hooks like useState and useEffect in Client Components, or data fetching libraries like SWR or React Query. Handle loading states and errors. Support real-time updates.

Server Actions allow form handling and data mutations directly from Server Components. Use 'use server' directive. Support progressive enhancement. Handle form submissions securely.

Use fetch cache options or React cache function. Configure cache behavior in fetch requests. Support cache revalidation. Handle cache invalidation.

Fetch multiple data sources simultaneously using Promise.all or parallel routes. Improve performance by avoiding waterfall requests. Handle loading states independently.

Create loading.js files for automatic loading UI. Use Suspense boundaries. Support streaming and progressive rendering. Implement loading skeletons.

Handle sequential data fetching where each request depends on previous results. Manage dependencies between requests. Implement efficient loading patterns.

Implement on-demand revalidation using revalidatePath or revalidateTag. Handle time-based revalidation. Support cache invalidation. Manage revalidation triggers.

Implement request deduplication, caching strategies, parallel fetching. Handle data preloading. Support prefetching. Implement performance optimizations.

Create error.js files for error handling. Implement fallback content. Support error recovery. Handle error reporting. Manage error states.

Use Server Actions or API routes for data mutations. Handle optimistic updates. Support rollback mechanisms. Implement mutation strategies.

Implement WebSocket connections or server-sent events. Handle real-time updates. Support data synchronization. Implement real-time strategies.

Validate data on server and client side. Handle validation errors. Support schema validation. Implement validation strategies.

Implement client-side storage strategies. Handle offline support. Support data synchronization. Implement persistence patterns.

Use prefetch methods or preload data during build. Handle route prefetching. Support data preloading. Implement prefetch strategies.

Implement secure data fetching patterns. Handle authentication/authorization. Support data encryption. Implement security measures.

Create custom caching logic. Handle cache invalidation patterns. Support distributed caching. Implement cache management.

Manage nested data structures. Handle circular references. Support data normalization. Implement relationship patterns.

Handle multi-client data sync. Implement conflict resolution. Support offline-first patterns. Manage sync state.

Implement data structure changes. Handle version migrations. Support data transformation. Manage migration state.

Track data fetching performance. Handle analytics integration. Support debugging tools. Implement monitoring strategies.

Implement scalable fetching patterns. Handle large datasets. Support pagination strategies. Implement performance optimization.

Create comprehensive test suites. Handle mock data. Support integration testing. Implement test utilities.

Implement end-to-end encryption. Handle key management. Support secure transmission. Implement encryption strategies.

Handle API versioning. Support backwards compatibility. Implement version migration. Manage version state.

Create comprehensive API documentation. Generate type definitions. Support example usage. Implement documentation updates.