I used Scheme for a while so I like using recursion when loops get a bit hairy, but Guy Steele's talk on Parallel Programming* made me aware of the limitations of that way of working. Now that I've switched to Common Lisp I try to think about the algebraic properties of my functions so I can apply them using lparallel's preduce.

* https://www.infoq.com/presentations/Thinking-Parallel-Progra...