[atonse]

That made me wonder, since bun natively supports typescript, is it already using some kind of rust implementation of typescript?

[0x6c6f6c]

Bun does zero work in relation to TypeScript's type system. Since it's a strict superset, it is "simply" stripping types to execute the resulting JavaScript. That is effectively what it boils down to.

TypeScript is the most complex type system in existence. I am unsurprised it is difficult to port, but I am still a bit surprised by the length of the project thus far.