Comment by yoran

We use it extensively in our codebase. We started without any types, and added Sorbet later. It's similar to Typescript as that you can gradually sparkle your code with types, building up the typing coverage over time.

I just completed a big refactoring. We have a good suite of tests. But Sorbet has provided an added layer of confidence. Especially when it comes to the treatment of null values. Sorbet will raise an error if you try to call a method on an object that may be null. So it forces you to think through: what should happen if the object is null?

So the tests combined with Sorbet typechecking made that we could just almost blindly deploy refactoring after refactoring, with only a handful of bugs for several 1000s of lines of code changed.