''there's always lots of state to keep track of, rearranging of values, handling special cases, and carefully working out how all the pieces of a system interac

''there's always lots of state to keep track of, rearranging of values, handling special cases, and carefully working out how all the pieces of a system interact'' These are the skills actually that are needed to implement an RB tree (lot of special cases to handle, hard to organize the code well), although I have never been asked to implement any balanced tree on an interview.