[Zalastax]

I instead proclaim that it brings you the best of both worlds. Finding the right mix of static/dymamic is a balance act but if you do so you get the benefits of static types (safety, documentation, tooling) and dynamic types (fast prototyping, not having to write convuluted code to please the compiler). What are the killer features that gradual types lose out on?

[int_19h]

As the old saying goes, "there's nothing more permanent than a temporary solution".

In the context of software development, it means that "prototypes" get shipped as production code all the time.

[Zalastax]

Sure,and lots of codebases are completely untyped. I find it great that you can opt out of the theorem proving that type checking is when crunch time comes. As such it functions as a loan and your organization should strive to pay back the debt when it can. Nothing can save you if you never get a calmer period.

[cannabis_sam]

I think it’s the worst of both worlds, you still have to deal with types (often manually even), but you can’t trust your types since they’re not pervasive.

The killer feature is global type inference. I pretty much prototype in Elm as fast (or faster) than any dynamic language, and when the code compiles it’s free of runtime error except at the boundaries (i.e JS interop). This allows me to focus on fixing error arising from my misundetstanding of the problem (and my general incompentence).