I'm building something like this that you can run in your own cloud!

https://flexenv.com/

It's nowhere near advanced as boxes.dev but it's built on the premise of running on any cloud. Indeed I have it running on two different bare metal server providers and I'm about to add a third (Azure) as I'm using my day job as my first customer.

Can I grab your contact details and schedule a demo?

Thanks a ton for the feedback. Yeah, this is something we'll try to solve in the long term. One of the things that makes this work really smoothly for setup and speed is the ability to have a template box that you can instantly snapshot and fork (disk and RAM) to spin up new machines. There aren't many sandbox providers that do that well for running a full app and development environment, but I'm sure there will be more over time. And the per-second pricing means that you only pay when your agent is running.

You could use VPS, but spinning up and down boxes on inactivity takes a long time, and making changes to the template for new machines is less trivial there. If you're only paying for 1 VPS box, then you lose the "multiple independent machines" benefit, and I imagine things start to get more expensive even in the VPS world when you have 10 of them running at the same time (one per thread).