I basically learned Haskell at my first job (writing a compiler), and it was pretty easy to productively contribute starting on day 1, especially because there seems to be less risk of breakage than in many other languages. I also helped teach it at the next job, and developers found it pretty easy to pick up, just different from what they were used to.
Prior to this, I had some experience using it for hobby projects, but there was a lot more to learn for real-world use. My colleagues and I helped each other learn new concepts and write better code, as best we could, but we did end up making some questionable design decisions. I think you still need an experienced Haskeller to advise on good program architecture.
Prior to this, I had some experience using it for hobby projects, but there was a lot more to learn for real-world use. My colleagues and I helped each other learn new concepts and write better code, as best we could, but we did end up making some questionable design decisions. I think you still need an experienced Haskeller to advise on good program architecture.