Very much this. I’ve overseen this process for one of my clients and we’ve seen build + deploy times go from 5-10 minutes down to around 1-2m. This was down to increased performance, improved caching, and being about to cut out some minor workflow setup steps.

So 10x cheaper and 5x the performance.

Still using GitHub Actions, but now just using self-hosted runners.

Well, the point was that if 4 concurrent `git push`es saturates up to 1500 vCPUs then you'd need 16 of those hetzner dedicated servers (which you have to manage the uptime for) that you're paying for for the entire month. ~4 pushes is a very small amount and an org with a few dozen or so engineers will regularly see peaks higher than this.

Additionally, you'd have to ensure some isolation across your test runs (either by running the test suites in ephemeral containers, or VMs) which is additional engineering work for something that isn't business critical.