Since you're here, I was just thinking about how feasible it would be to run a microVM-per-tenant setup like this on Fly. I guess it would require some automation to create a Fly app for each customer. Is this something you all have thought about?
Extraordinarily easy. It's a design goal of the system. I don't want to crud up the thread; this whole "container vs. VM vs. dedicated hardware" debate is dear to my heart. But feel free to drop me a line if you're interested in our take on it.