I learned Haskell for a year and went into various books. After that I tried to contribute to a relatively simple open source projects and I realized the real world Haskell is so different than books, then I got discouraged and stop. These days I wanted to pick up Haskell back again, is there any updated resource you can recommend for doing real world Haskell?
Haven't read it but there's a book called "Real World Haskell", which I thought was funny considering your question. Right now I'm really enjoying "Functional Design and Architecture"[1] by Alexander Granin (it does assume you've already got some experience). In addition, make sure to revisit Stephen Diehls "What I Wish I Knew When Learning Haskell"[2].
I'm currently going through Haskell Programming From First Principles (https://haskellbook.com/) and am liking it a lot. It's only been a few weeks so I can't say for sure, but it seems like it's comprehensive enough (1200+ pages) where you'd pick up what you need for real world stuff. To some extent at least; in practice there's probably no substitute for just getting real world experience.
PS: Hi Christian! You were a TA when I was a student at Fullstack :)