nub is slow then ts-node.

[NarHakobyan]

I've tested nub on our nestjs project, it the startup of nub went up from 5s to 15s.

Plain TS: nub wins. Add decorators and it inverts and goes linear at ~9 ms/file vs ts-node's ~1 ms. Profiling the decorator-only case gives the same shape as the real run (87.1% in resolveSpec). Reason: nub's transformer emits @oxc-project/runtime/helpers/decorate / decorateMetadata / decorateParam — 2929 of 6331 cached outputs on this machine import them — roughly three extra import sites per decorated class. That's every file in a Nest codebase. ts-node sidesteps it entirely with require.extensions['.ts']: plain CJS resolution, no path↔URL round trip, and tsc emits decorator metadata inline.

Then watch mode multiplies it

nub --watch is Node's native --watch (its own Restarting 'src/…' output) — full respawn, nothing carried in memory, so every edit repays the whole ~10 s. ts-node-dev --respawn restarts only the child; measured restarts were 697 ms and 1151 ms against its own 2446 ms cold start, consistent with compilation state being reused.