Bun is still faster, and Bun's testing is insanely fast -- I had a test suite that would take 30 seconds with Jest that finished in 800ms with bun. Plus Bun's networking performance is insane compared to Node, and you can have a lot more concurrent clients in a light vpc (think 1gb).

I think you're saying the integration of fast testing and building is what moves the needle for you? Because esbuild is limited to the build portion. I haven't explored fast testing alternatives to pair with esbuild.

And Go is much safer as implementation language.

Go is safer for networking heavy/performance critical services, but for anything that's IO/upstream limited the performance of Bun and Go will be comparable and there are more people who are node proficient/it lets people work across the stack with the same tooling.

What has that to do with Zig?