>Caching with Swatinem/rust-cache. It helps, but there’s a trap. A workflow run can only restore caches from its own ref or the default branch, and GitHub evicts caches unused for 7 days.

>A self-hosted runner for the heavy builds. This was by far the biggest win, 90 minutes down to 40. It also means I now maintain a build server.

WarpBuild (https://www.warpbuild.com/)[1] solved this for me.

1. You can cache into your own s3 bucket, so you manage eviction policy

2. They manage the infrastructure, or you can link in your AWS account. I have builds that run on spot instances that are requested when a build starts.

Then for the caching issue, I just have a scheduled job that reruns a build at midnight on the master branch.

[1] Not affiliated, found them through Google several months ago