Show HN: Thematic Crossword Generator

I mostly wanted to prove to myself that I could build and deploy a non-trivial app — complete with user login, UI etc even though I'm more a backend guy.

The fill algorithm is based on Knuth's Dancing Links (DLX), so it should be quite fast. The backend is hosted on Fly.io, and I’ve scaled it up to 10 machines for this submission — let’s see if that’s enough!