Jobs that exclusively or almost exclusively used Haskell & Scala: (1) backend engineering for a large bank (you can likely guess), (2) machine learning at a large education technology company, (3) machine learning at an ad tech company.

My favorite two languages are Python and C. There are certain things I like about Rust, Go and Julia.

I dislike Java and C++ (just personal preference).

I dislike Scala a ton. Really disergonomic and overly complicated.

I like Haskell a lot. Very clean, fun to write, it just doesn’t confer any serious advantages over other language choices and does suffer from difficult-to-extend designs in business use cases, but probably very good for academic work, pure software or research projects. It’s very nice language, I just wish it wasn’t hyped as a transformational way of thinking or as a panacea for all the normal annoying problems with business software.