Right, so you agree with him. TypeScript was too slow and switching to Go was the right choice.
They could have rewritten the Typescript compiler in better Typescript. I just peeked at random files in last TS compiler branch before the port (v6.0.3). Simply put, I would not have written it that way. That style would surely hit it performance cliffs.
If anyone from the TS team is lurking, I can be paid a reasonable consulting fee to talk lol. No free work from me, I'm already too busy with my own language.
Or contract me to match (or maybe even exceed) the Go port.
But I suspect Anders and the TS team are plenty satisfied with their Go port. So maybe, it'll be more of an educational adventure.