Building Scalable Web Apps with Next.js

The App Router Era

With the introduction of the App Router, Next.js fundamentally shifted how we build React applications. Server Components are now the default, changing our mental model.

Server Components vs Client Components

By default, everything in the App Router is a Server Component.

Rule of thumb: Keep components on the server until they explicitly need interactivity (like onClick, hooks, or browser APIs).

// This runs only on the server
export default async function Dashboard() {
  const data = await fetchUserData();
  return <Profile user={data} />
}

Optimized Data Fetching

Next.js extends the native fetch API to automatically memoize requests and handle caching.

• Force Cache: Static generation.
• Revalidate: Incremental Static Regeneration (ISR).
• No Store: Dynamic, real-time rendering.

By leveraging these rendering strategies appropriately, we can build web apps that are as fast as static sites but as dynamic as single-page applications.