Fair enough, I just disagree with the premise that heavily relying on the type system actually lets you think less hard about how to implement your code. In my

Fair enough, I just disagree with the premise that heavily relying on the type system actually lets you think less hard about how to implement your code. In my experience, defining the types you'll use at module boundaries is the actual hardest part. The stuff in the middle is usually straightforward until you realize you need sub-modules, at which point you're defining module boundary types again.