I like the ad-hoc solutions. They correspond more closely to what your code is actually doing. I used to work on a Scala code base that heavily used a functiona

I like the ad-hoc solutions. They correspond more closely to what your code is actually doing. I used to work on a Scala code base that heavily used a functional style with monads, custom operators, and elaborate type hierarchies. At the micro level these things seemed great, they removed a lot of "boilerplate", but when you zoomed out and tried to figure out how larger parts of the application worked it quickly became overwhelming because these language features made understanding what the program was actually doing much harder.