Merging a complete rewrite in another language in 9 days seems insane to me. Maybe I'm just too cautious but with something like this I'd split off as a separate binary and get some heavy use customers involved as testers first to see if it causes any unforeseen problems before slowly expanding it out.

I'd want to be pretty damn confident it won't cause any regressions before sunsetting the original codebase in favor of this one.

I don’t think you’re too cautious. Big upgrades and rewrites is somewhat of a „work hobby” of mine and this seems waaay too fast. I don’t know how the Bun canary process works and I guess their test suite is better than typical projects but still… I can’t imagine this working out well without testing it on a variety of big projects for a significant amount of time.

There’s probably loads(?) of observable behaviors that people rely on, consciously or not. Even _if_ the new thing is 100% spec compliant, it might still be breaking or otherwise problematic for heavy users.

That said, I’d love to be proven wrong. I use Bun from time to time on small stuff and I enjoy it, so I wish them well (:

> too cautious

No, you are perfectly normal.

The people who in one week decided to replace the whole codebase for a widely used tool with code no human has seen are the crazy ones.