PART 01

Core concepts

Native ESM, the unified Rolldown architecture, dep pre-bundling, the module graph.

1.1Native ESM and Browser-Native ModulesThe foundation of Vite — what are browser-native ES Modules? Where does the `<script type="module">` boundary sit? Why can Vite's dev server start without bundling?
1.2Vite 8's Unified ArchitectureHow does Rolldown unify the dev and build phases? What is the architectural evolution compared to the dual-engine era of Vite 5/6/7?
1.3Dependency Pre-BundlingWhy does Vite pre-bundle node_modules? What changes when Rolldown takes over pre-bundling? How does the .vite/deps cache work?
1.4Module GraphVite maintains a complete module dependency graph in memory — it is the foundation of HMR and the core of the Environment API. You can't truly understand Vite without understanding the Module Graph.
1.5Env Variables and ModesUnderstand import.meta.env, .env priority, VITE_ prefixes, envPrefix, loadEnv, HTML replacements, and the difference between mode and NODE_ENV.
1.6Source Features: CSS, JSON, Glob, WASM, and WorkersVite includes modern source handling for CSS, JSON, import.meta.glob, dynamic imports, WebAssembly, Web Workers, and CSP-sensitive assets.