What about runtime stuff? I've found Haskell is very good at abstracting away your concerns about the runtime considerations and sometimes it will come back to bite you. I mean all that stuff you want to see into when you're running your app in production, like caching, function invocation times, threads etc.
Can't really comment on that - most of the code I use is built on the awesome Haxl[0] so we never have to worry about those things. I'm curious what other people think though
