A mix, but a majority Ruby, with some shell scripts and Terraform.
My gut feeling is that it would generalize to typed languages, Go, Erlang, even Haskell etc, but maybe some of them make life easier for the reviewer in some ways? What are your thoughts on that?
I've worked with some junior developers and my experience has been the same as yours. We work primarily with typed languages. With junior developers I see two ways it goes: either they write code that does not take advantage of the type system, typing everything as basic string or numeric types. On the other end of the spectrum, those who go to the extremes where they build a complicated type hierarchy with abstractions more complicated than the problem space requirements
My gut feeling is that it would generalize to typed languages, Go, Erlang, even Haskell etc, but maybe some of them make life easier for the reviewer in some ways? What are your thoughts on that?