React Server Components: A Practical Migration Guide

React Server Components changed the default mental model for the framework. Components no longer have to ship to the browser, and the rendering boundary is now a deliberate choice rather than an accident of folder structure. That power is useful, but it also creates new ways to build slow, fragile applications if used carelessly.

Start the migration with the data layer. Identify the routes whose first paint depends on fetched data and move those fetches into server components. The bundle shrinks, the waterfall flattens, and the client takes on only the interactive leaves rather than the entire page.

Resist the temptation to convert everything. Forms, charts, editors, and anything with rich client state belong on the client side. The 'use client' directive is not a step backward — it is the contract that tells the framework where interactivity lives.

Caching is the part that bites teams. Server components compose multiple cache layers: the request memoisation, the data cache, and the full-route cache. Invalidate them deliberately. Set explicit revalidation tags on every fetch that backs a mutation, and audit the cache behaviour of every shipped route.

Measure before and after. Time to first byte, total transferred JavaScript, and Largest Contentful Paint will tell you whether the migration actually helped. If those numbers do not move, the architecture change was not the bottleneck — and that is a useful answer too.