I have a library that is much like every other library in javascript. I decided to try TypeScript on it once as a test. The idea was to implement all the correct interfaces so that people couldn't call the wrong chain of methods. The interface list was almost the same size as my entire codebase.

I think TypeScript is essentially for retards. It is like "we need to lock everything down so the mediocre people we have to hire on mass can't break anything".