I'm running https://info-beamer.com, a digital signage hosted service using the Raspberry Pi. It started as a for-fun project 8 years ago when I decided to do the digital info system for a local hacker conference and didn't find anything that allows quick prototyping and rapid iteration/live coding of content. I then switch from "desktop Linux" to Raspberries and added a web based service around the fairly low-level command line tool. It's my main source of income for 4 years now.