nextjs-15

Next.js 15 App Router structures layouts and pages using specific file conventions like layout.tsx and page.tsx. These files define shared UI wrappers and route-level content, enabling scalable application architectures through nested routing.

Data fetching in Next.js server components executes on the server before rendering. You handle streaming dynamic content by wrapping asynchronous components in Suspense boundaries, progressively sending HTML chunks to the client.

Server actions in Next.js handle server-side mutations and form submissions directly within server components. You define asynchronous functions marked with specific directives to execute secure backend logic without creating separate API endpoints.

Middleware in Next.js intercepts requests to provide route protection and execute redirects. It runs before a request completes, allowing you to verify authentication, check user roles, and redirect unauthorized access securely.

Route handlers in Next.js are needed when building RESTful API endpoints or handling webhooks. Unlike server actions which handle form mutations, route handlers process standard HTTP methods like GET and POST for external integrations.

Next.js 15 supports dynamic routing through URL parameter file conventions and automatic metadata generation. You define dynamic route segments and export metadata objects to programmatically configure page titles and meta tags.