nextjs-advanced-routing

To handle form submissions with Next.js Server Actions, use the `useActionState` hook for state management and the 'use server' directive in action.ts files to execute server-side mutations directly from client components.

Parallel Routes in the Next.js App Router allow you to simultaneously render multiple pages within a single layout using named slots, enabling complex UI patterns like modals and independent sidebars without full page reloads.

You cannot set cookies directly from a client component, but you can trigger a Next.js Server Action using the 'use server' directive to securely execute server-side code and modify cookie headers from the server.

The best way to create API endpoints in the Next.js App Router is using Route Handlers, which allow you to build web request and response APIs directly within your routing structure using standard Web APIs.

Use Intercepting Routes in Next.js when you need to intercept a routing action to show a temporary UI like a modal over the current page, preserving the original context while supporting direct URL access for deep linking.

Improve perceived performance in Next.js by wrapping slow asynchronous data fetching components in Suspense boundaries, which allows the application to stream HTML and progressively render UI as server data becomes available.