Other founder of Depot here. AWS is pretty close to this idea with their Warm Pools [0]. But for our use case, they're just too slow to react to changes. We observed 60s+ to notice a change and actually start the machine. That doesn't work when we need to launch the machine as quickly as possible in reaction to a pending GHA job.

That said, I think this is a problem they could likely solve with that functionality, and we'd love to use it.

[0] https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-au...