You can try and take some old JS lib and annotate it in TS. It'll work. It'll be very clunky, and full of any/unknown. There's a reason why strong static typea

You can try and take some old JS lib and annotate it in TS. It'll work. It'll be very clunky, and full of any/unknown. There's a reason why strong static typeable code looks the way it looks (basically functional programming). You can type a monad chain, because it's a container type for arbitrary types interacting, but you can't easily type a switch nested in a for loop that uses a queue to walk a tree. Of course the flip side is that to walk a tree functionally you need recursion schemas, and they are ugly/complex.