Quickz is built on a SvelteKit, powered by a Node.JS backend that handles the database and creates a thread for each game room. I chose MongoDB for the database, because I found that the non relational approach helps with the complex structure of the decks. It's self-hosted at home using a Dell Optiplex running Ubuntu Server right now, but eventually I'll have to move to a better hosting setup. :)
Currently it only supports Google login, mostly because I don't trust myself enough to safely manage and store credentials. Many schools are already in the Google ecosystem, so for now it should be enough. However, I'm not a huge fan of my website depending on a single third party, so I'm going to have to work on that soon.
The host's screen is just a mirror of what the players will see, and so you can't interact with it, apart from going forwards and back. I think this needs to be communicated better, so I will be also working on improving the UI/UX on that.