>> Mutable state can be a huge pain in the ass [..] 8I don't know, I think it's a point where education fails* I'd argue that the problem with software quality

>> Mutable state can be a huge pain in the ass [..] 8I don't know, I think it's a point where education fails* I'd argue that the problem with software quality is not so much in the (ab)use of mutable state, but the fact that (especially in enterprises) software often reflects the organizational structure of the people who worked on it. Exhibit A: the software solution where every tiny part of the system is developed by some (semi) random group of people that often changes, doesn't directly communicate with any of the other groups, doesn't bother to much with the 'architecture' of the complete system (a big ball of mud), and has no interest improving either the overall architecture of the system, or any of the components outside their scope. Add pervasive mutable state into this mix, and you have a recipe for disaster. That's not to say the mantra 'eliminate (almost) all forms of mutable state' will improve this problem much.