Professional Haskell experience is desired but not required. Haskell expertise is required.
BA/BS in Computer Science, related technical field or equivalent practical experience.
Minimum 4 years experience writing scalable, reliable software.
Interestingly I have the exact opposite perspective. Writing imperative or OOP code requires me to be excessively disciplined. It is extremely easy to build un-maintainable spaghetti. There is a whole cottage industry of methods for your discipline of choice: Clean, SOLID, TDD, etc. All these disciplines seem to boil down to the same systemic result, push effects to the edges of you program so you can more easily test, evolve and maintain. Functional programming (of the typed variety) tends to allow me to write garbage code, that is testable and can be easily evolved and maintained because the paradigm encourages me to be a good actor.
I've refactored production code in imperative languages and typed functional languages and only one of them allowed me to make HUGE sweeping changes with ease and high confidence.