From Next.js to Pareto: What Changes and What Stays the Same

You know Next.js. You know file-based routing, layouts, loaders, SSR. You probably also know the pain: server components vs client components, the "use client" dance, mysterious hydration errors, and a 233 KB client bundle before you write a single line of app code. Pareto gives you the same SSR patterns — but without the complexity. Standard React components, Vite instead of Webpack/Turbopack, and a 62 KB client bundle. This post walks through exactly what changes when you move from Next.js to Pareto, and what stays familiar. The mental model shift Next.js (App Router): Every component is a server component by default. Want useState? Add "use client". Data fetching happens via async server components or route-level generateMetadata. You're constantly thinking about the server/client boundary. Pareto: Every component is a regular React component that runs on both server and client. Data fetching happens in loader.ts files — a pattern borrowed from Remix. There's no "use client" directi