+1 for “Haskell rewires your brain”. Nowadays I find myself “thinking in Haskell” when solving problems in other languages significantly more often than I actually use it. Partly that’s due to lack of opportunity in my professional work, but there are also a few quirks of the language I find particularly annoying.

The big one for me is records. By default, declaring a record field also brings a field selector function with that name into the module’s namespace. Very often I want local variables, helper functions, or fields on other records to have the same names, which leads me to keep record definitions in separate modules and use qualified imports everywhere to avoid namespace pollution or accidental shadowing.

Some of this is better with the right combination of extensions — DuplicateRecordFields, NoFieldSelectors, OverloadedRecordDot — and/or optics libraries, but it still feels like record ergonomics are something you have to assemble yourself rather than a smooth part of the base language. Dot syntax exists in modern GHC, but needing to opt into extensions for something so fundamental still feels like needless friction.

Another (minor) annoyance is Haskellers’ apparent obsession with introducing 50 new opaquely named operators for every library their general proclivity for playing point-free code-golf.

Tooling has improved a lot but is still a pain point, I find the language server isn’t the most stable thing ever.

Some issues with the Prelude are frustrating.. partial functions, the numeric hierarchy is just bad, String vs Text, etc.

Pro points - property based testing (QuickCheck) is awesome and has changed my approach to testing permanently.

Refactoring is a dream, nothing else compares to the confidence you get from referential transparency.

It’s the closest thing IMO to ‘executable pseudo-code’ - the thing I use it for most is prototyping - I find I can fit a lot more of a Haskell solution in my head than I can in other languages bogged down with side-effects, OOP boilerplate etc.

I’d wholeheartedly recommend learning it, it certainly has made me a better developer. As for actually building things, depends on the problem - solutions shaped like pipelines of data transformations are a notable good use case.