Unbundled dev server are nimble, fast, and naturally incremental. That's how we made Vite's HMR so fast. But it has its limitations: one of the major pain points when using Vite in large-scale applications is the slow dev server page load speed.
The upcoming Full Bundle Mode for `vite dev` (powered by Rolldown) completely resolves this problem. In developing this, we actually had to invent a whole new HMR implementation (inspired by Vite's original unbundled HMR) to ensure HMR stays decoupled from application size even in full bundle mode.
The result is the best possible DX: in an app loading 10k React components, full bundle mode offers 15x faster startup & 10x faster full page reload compared to unbundled mode, now faster than rspack/rsbuild in both metrics, while retaining instant (and even faster) HMR.