Fullstack React: Server-first or Client-first?

Fullstack web applications aim to combine the performance benefits of server-side logic with the dynamic user experience of client-side single-page apps. In the React ecosystem, there are two main approaches to this: On one side, React Server Components (RSC) push most of the rendering to the server, sending only truly dynamic content to the client. On the other side, traditional Server-Side Rendering (SSR) techniques are used to boost the performance of client-side applications.

In this talk, I’ll walk you through both approaches using practical examples with Next.js and TanStack Start. Together, we’ll explore where each technique shines, how they affect existing codebases, and whether it might still make sense to stick with purely client-rendered single-page applications that don’t rely on a server at all.

This talk is aimed at frontend and backend developers as well as software architects interested in modern web development.