I recently moved our GutHub CI to a self-hosted runner and it reduced CI times for all jobs by ~5x.
One frustrating part is that a single GitHub runner can handle one job at a time, and our repos have 4-8 highly parallelized jobs. So we need multiple runners. To do this in an economic way, I made a Docker image and run 10 instances of it a single dedicated host from Hetzner. For ~$50/mo, we have unlimited CI and job run as fast as theoretically possible.
The CI box has no inbound ports open to the internet, and the OS is set to auto-update, so the maintenance burden is low.
One frustrating part is that a single GitHub runner can handle one job at a time, and our repos have 4-8 highly parallelized jobs. So we need multiple runners. To do this in an economic way, I made a Docker image and run 10 instances of it a single dedicated host from Hetzner. For ~$50/mo, we have unlimited CI and job run as fast as theoretically possible.
The CI box has no inbound ports open to the internet, and the OS is set to auto-update, so the maintenance burden is low.