We don't limit concurrency on the builder VMs. When you create a project you are effectively getting a dedicated build VM with a persistent SSD cache for each architecture you want to build for. We run native BuildKit on the VM and connect your `depot build` directly to the builder instance via mTLS. So your concurrency is unlimited with Depot as well (or at least as unlimited as BuildKit will allow for).
How does this work if I have 5 builds for a single project at the same time?
In our current setup it takes a bit longer to boot, but concurrency is effectively unlimited. I don’t imagine that is true for Depot?