An interesting middle ground here is when the editor can annotate the function signature's types for you, with code lens type features. Of course this only wor

An interesting middle ground here is when the editor can annotate the function signature's types for you, with code lens type features. Of course this only works for people who happen to be in such an editor. Another issue I ran into recently was you can add a new type to your program, and break existing code. Where the type inference was able to deduce the type, and your new type appears to also be compatible, and now things don't compile and it is very mysterious why not! There can be some interesting big wins by leaving types off when possible though, like super easy refactoring. Just start passing ints to a big chain of functions and you are done. No need to change the signature of a big chain of functions.