TypeScript 7 Rewrites Compiler in Go, 10x Faster
TypeScript 7 RC dropped with its compiler fully rewritten in Go, delivering roughly 10x faster build times. This is a significant architectural bet: Microsoft is trading the self-hosting purity of a TypeScript-compiled-in-TypeScript compiler for raw performance. The HN thread is mostly positive, with builders immediately noting this affects every editor, CI pipeline, and monorepo that touches TypeScript.
The pattern here is that compile-time performance has become a real competitive differentiator. The same instinct is visible in the epoll vs. io_uring thread and the AVX-512 SIMD decoding post, where people are digging into low-level throughput gains that compound at scale. Developers are no longer satisfied with 'fast enough' when 10x is demonstrably achievable.
The counterpoint some raised: rewriting in Go means TypeScript contributors now need to know Go, which changes the open-source dynamics. The self-hosting compiler was a statement about the language eating its own cooking. That's gone now.
So what?
If you run large TypeScript monorepos, this is worth testing immediately because the CI time savings compound across every engineer and every deploy. More broadly, if you're building developer tooling, compile and build speed is now a feature people will switch products for, not just a nice-to-have.