One of my favorite exercises for staying sharp is doing code katas. I particularly enjoy doing code katas on Codewars because of the way in which they track your progress by programming language and the way in which the katas are tagged by topic.

I am currently aiming to get to the rank of 1 kyu by the end of 2021, I’ve mostly been doing Python and JavaScript katas involving interpreters, parsers, compilers, and advanced language features. This is great practice with stuff that I would never get to see in my day job, like the Shunting Yard algorithm or ROLLUP in SQL.