I'm a Scala developer and I use its type system to approximately its full potential and I prefer it to other languages precisely because of its static-ness. Wit

I'm a Scala developer and I use its type system to approximately its full potential and I prefer it to other languages precisely because of its static-ness. With a powerful type system you effectively eliminate certain problems from happening, like I once had a bug that I couldn't understand, yet I eliminated the possibility of it happening. And I prefer it precisely because I'm not smart enough for the problems I'm working on, so I prefer having a static type-system holding my hand. That said ... > On the other hand I can get by with writing Haskell and OCaml without writing tests Tests and static type-safety serve different purposes. If you end up writing tests for properties that should have been inferred by a static compiler, then you're using the language in a wrong way or you've picked the wrong language for the problem at hand. When working with a dynamic language, I don't need to write tests just to see that my code works. It's because I work with a REPL and in terms of happy paths, that's just as effective as having a static type system. And surely having a compiler is very cool when refactoring, however we tend to miss the fact that (a) the kind of refactorings we are doing are very superficial and for architectural / design refactorings the compiler doesn't save you and (b) in a dynamic language there is less need for refactoring, because you don't end up modelling the whole world through types. > I don't want to start a discussion here on typed vs untyped I'm also thinking you're making a confusion. Dynamic languages can be strongly typed. A language Clojure is very much typed. The difference is in the moment those types are used, at compile time or at runtime. This is important, because a dynamic language like Clojure can do optional typing when you want it. Of course, something like core.typed will never be as expressive and potent as Haskell's type-system, however this leads to gradual evolution - at first you don't have a well defined shape for the data you're working with, so you can enjoy the relaxed rules and protocols of Clojure and afterwards you can start introducing type definitions with core.typed or with prismatic/schema. As I said, I'm a developer that leans on the static side of the argument, however this debate will never be settled simply because which tool is the best depends on the problems you're trying to solve, therefore people will never agree on anything, because people are always thinking from their "personal experience".