Ask HN: What niche business domain do you find fascinating?

Hi HN, I currently work at a FAANG and while I’m in expert in our products and processes, the knowledge isn’t very useful outside of my company. In the past I’ve been more motivated when I’m working on industry problems that are “bigger” than my company. Even “boring” domains (payments, finance) are really interesting once you realize how deep they are.

What business domain have you worked in that you find interesting?