Ask HN: Fun and unexpected applications of Computer Science?

I am giving a talk to fresh graduates of a coding bootcamp, I would like to show them that CS is more than coding, and that there can be a lot of fun applications, and how having fun can feed learning.

I have seeded my list with the following fun and unexpected applications, but I would appreciate more pointers:

* Applications of ML in art, e.g. DALL-E, DeepDream, OpenAI's MuseNet and JukeBox.

* Computational origami, highlighting some of the work of Erik Demaine.

* A couple of examples of how some ideas from CS can be applied to day-to-day life, inspired by "Algorithms to Live By" by Christian and Griffiths, e.g. looking at the exploit vs explore trade-off when selecting a restaurant in town.

* Knuth's papers on The Complexity of Songs, and The Toilet Paper Problem.

* A couple examples of esoteric languages.