TypeScript 5 in Practice: The Few Features That Actually Changed My DX

I upgraded a medium‑sized React codebase to TypeScript 5 and kept track of what mattered beyond the release notes. • Const type parameters: removed a bunch of overloads in utilities — generics finally read like plain English. • satisfies: validate config objects at compile time without losing literal types — perfect for feature flags and API client maps. • Faster project builds: not ‘50% faster’ everywhere, but cold builds and project references felt snappier on CI. If you’re on TS 4.x and using heavy generics, TS5 pays for itself — mostly by letting you delete clever code.