[citizenpaul]

I thought a big part of the reason for type systems was a sort of self documentation/contract? Especially if you need to work on an unfamiliar system with bad documentation. Also what about system boundaries? I prefer typed languages personally.

[galaxyLogic]

The benefit is not only about "documenting the contracts" but documenting the contracts in a way that we can trust those contracts can not be violated when the program is running.

That is a very good thing to help us reason about the program, we have invariants we know must hold true if the program does not stop in a type-error.