I’m finishing up Haskell Brain Teasers (https://pragprog.com/titles/haskellbt/haskell-brain-teasers/)

It’s much shorter than my first book, Effective Haskell, and leans more advanced, especially toward the end. Although the format is puzzle focused I’m trying to avoid simple gotcha questions and instead use each puzzle as a launchpad for discussing how to reason about programs, design tradeoffs, and nuances around maintainability.