You build React apps: do you even know how?

Abstract

React developers rely every day on tools like Vite, Webpack, or Rollup, but what actually happens when you npm run build? What’s inside those “bundlers” and how do they turn your JSX and node_modules soup into fast, production-ready apps?

In this talk, we’ll reverse-engineer the React build pipeline from the ground up. We’ll explore how bundlers parse your code using ASTs, resolve dependencies, apply tree-shaking and code-splitting, and implement dev-time features like Hot Module Replacement. We’ll also see what makes Vite fundamentally different, and why it matters for React performance and DX.

Whether you’re debugging a slow build or just curious what’s behind the curtain, this is the deep dive you didn’t know you needed.