Mastering Next.js 15: Server Actions & Partial Prerendering

Next.js has become the de-facto framework for building React applications, and with version 15, Vercel has once again raised the bar. Two features, in particular, stand out: Server Actions and Partial Prerendering (PPR).

Server Actions: Simplifying Data Mutations

Gone are the days of setting up separate API routes for simple form submissions. With Server Actions, you can define asynchronous functions that run securely on the server and call them directly from your components.

async function createInvoice(formData) {
  'use server'
  await db.insert(formData);
}

This reduces boilerplate and keeps your logic co-located with your UI, making the codebase easier to maintain and reason about.

Partial Prerendering: The Best of Both Worlds

PPR is a hybrid rendering model that combines static and dynamic content in the same response. The shell of your application is served instantly from the edge (like a static site), while dynamic parts are streamed in parallel.

This results in outstanding TTFB (Time to First Byte) without sacrificing the dynamism required for personalized apps.

Why It Matters

These improvements aren't just technical niceties; they directly impact user experience and SEO. Faster load times mean lower bounce rates, and simplified architecture means faster shipping velocities for your team.