I’m working on https://screenplay.dev, where test every change against a battery of open source iOS apps (Wikipedia, signal, etc). We started on GitHub actions, but found it much cheaper to buys ~4 Mac mini’s and run them in the office. It takes a little love to keep them up to date and stable (maybe an hour a week), but in return we get cheap, debuggable Mac computer. I like that more offerings are appearing, but at this price, we’ll stick to our furnace of Mac mini’s for now.