This Repo contains a runnable server for the UI of a ranked-choice voting system. I didn't get super far into things, but learned a ton about how Phoenix LiveView works, and it's super fun tech. The website tracks active users, and makes real-time updates as they change. There's a drag-and-drop API for re-ordering choices.
All in all I think Phoenix is a excellent successor to Rails (as in, I would 100% pick it over Rails for making a mid-to-large webapp). I did find there to be quite a learning curve though on socket broadcasting, and the nitty gritty details of LiveView at the stage it was in when I was working with it (still Beta).