I'm working on a custom trading web frontend for Localbitcoins. It's been an MVP for me for years, helping me live off my stack of sats very conveniently. It's multi-currency and just now multi-user, so maybe there's a chance to turn it into a real product, since P2P trading in that platform has been exploding in latam (where I'm from) and more recently in eastern Europe. Anyhow, it's a big part of my plan to escape my shithole country before I die.

PS: It's vanilla Node + JS on the frontend, but I'm moving as much as I can to Elm to help me keep my sanity. If I'd known better years ago, I'd go Elixir/Phoenix, but I really needed to hit the ground running back then.