The bun rewrite inspired me to be much more aggressive on porting code, rewriting code, or vendoring external dependencies to tailor them specifically to our needs in ways that doesn’t make sense to upstream.

I feel like it made me generally more ambitious in what I’d throw at a coding model, but also made me focus a lot more on our testing harness and keeping a lot of it at the boundaries outside the language specific parts.

Having been part of several huge rewrites before, some multi-year long, I definitely would consider bun’s rewrite an enormous success. To keep such a level of test and feature parity, and add improvements on top of it, is a massive engineering feat.