The frontend is in TypeScript (swc compiler) using web components and no libs. Experience has been good so far.
The quiz is specified in xml that maps one-to-one with the web components, and backed by an xsd. Shell scripts written in C for cross-platform support (as simple as `#!/usr/bin/tcc -run` at the top and chmod +x in Linux (if you ignore the fact that x-platform C is hard, since you've only got libc)).
The backend is in C, compiled with tcc and using wsServer for websockets, protobuf for a binary wire protocol and sqlite for managing game state (enabling the server to crash and continue after restart). Can be compiled on Windows with a win32 pthread layer I extracted from mingw (for tiny c compiler ofcourse).
Which is also why I had to stop myself: My own projects tend to get out of hand with way too many interesting side quests.