I didn't believe the TypeScript

I didn't believe the TypeScript 7 speed claims. So I benchmarked it on my own production app — not a toy repo.

1,358 source files. 260K+ lines. The live codebase behind lokerdollar.com.

One change: tsc → tsgo (TS7, rewritten in Go). Same tsconfig, same tree, --noEmit.

Cold type-check: 77.1s → 11.6s. 6.6× faster. −85% wall-clock.

Then the part most "10× faster" posts skip — I checked whether it still catches bugs. Seeded 4 classic type errors. Byte-identical diagnostics: same codes, same line and column. The speed isn't bought by missing errors.

But I'm not putting it in your CI yet — and here's the honest reason:

— It's a release candidate — The native binary drops the JS typescript API, so typescript-eslint type-aware rules, ts-morph, ts-node and ts-jest break — Custom transformers and incremental builds are still maturing

My call: run it now as a fast local / pre-PR check, and keep tsc as the authoritative CI gate until 7.0 ships stable. You get a 6.6× tighter local loop with zero risk to the pipeline.

The ~$190/year in saved runner minutes is rounding error. The real return is nobody waiting on a turtle.

#TypeScript #DevTools #WebDev