To be fair, it is very, very unlikely that I am better at type systems than someone working on TypeScript, so anything I'd suggest, you probably heard about, an

To be fair, it is very, very unlikely that I am better at type systems than someone working on TypeScript, so anything I'd suggest, you probably heard about, and is either already on your roadmap, or was a conscious design decision that we just happen to disagree about :) I think the javascript type system world is still evolving, and the only "wrong" thing to do is to say "Ok, its a solved problem, let's run away with THIS ONE and kill the others". As long as we still have at least 2 reasonably well known ones, I'm happy.