Postgres until now has been using cirrus-ci for CI. Unfortunately they're shutting down June 1st.

They had been a good fit for us because:
- some free credits so everyone could run some CI on their own
- supported providing own compute for more demanding cases (via GCP and self hosted mac HW)
- jobs ran in one-off VMs
- support for custom images allowed us to pre-install everything, keeping test times manageable
- VMs not containers was good for perf
- CI job definitions could be run locally

Any suggestions / experiences where to look next?
@AndresFreundTec We are using tart with gitlab-ci. It is not clear yet, if that will also get shut down in the near future, since that was their VM software, but at least for now it seems to still be maintained, so maybe that would be an option? For Windows we just use gitlab-ci with a custom runner, that starts libvirt VMs. It is quite flexible and probably could be made to fit most things, but it does take some effort to setup and maintenance as well as compute hardware.

However we already run our own Gitlab as well, so it is quite likely, that our solution is not a good fit at all for you. But I do think running your own CI hardware using open-source tools wasn't a bad idea.