nextjs-expert

Server Components in Next.js 14+ reduce client-side JavaScript by rendering on the server, while App Router enables organized file-based routing. Structure your app to keep heavy logic server-side, fetch data directly in components, and use streaming for faster page loads.

Next.js API routes handle server-side logic and external integrations. Implement caching strategies using response headers, revalidation tags, and incremental static regeneration to balance freshness and performance across your data layer.

Mark components with 'use server' or 'use client' directives to establish boundaries. Server components execute server-side for data fetching and secrets; client components run in the browser for interactivity. Proper boundaries minimize bundle size and improve security.

Yes. Migrate incrementally by adopting App Router alongside your existing Pages Router, converting components to Server Components where data fetching occurs, and leveraging Server Actions to replace API endpoints gradually while maintaining compatibility.

Server Actions are async functions defined server-side and called directly from client components, eliminating API endpoint boilerplate. API routes offer explicit HTTP endpoints for external integrations. Use Server Actions for internal mutations; API routes for third-party access.

Streaming sends HTML chunks progressively to the browser instead of waiting for the full page to render. In Next.js, use Suspense boundaries with Server Components to stream UI incrementally, showing critical content first while slower data loads in parallel.