In every language I’ve used where types can be inferred, almost everyone writes down the types of their top level functions (or at least the functions that are

In every language I’ve used where types can be inferred, almost everyone writes down the types of their top level functions (or at least the functions that are exposed to clients). I don’t think this is really a good counter argument. The only ways I know of to reliably make this kind of change (or just about any nontrivial change) to an interface are increasing version numbers and letting clients suffer or having a monorepo and fixing all the clients yourself