Zuul (https://zuul-ci.org/) was created for openstack to solve the issue of optimistic merges / PR queue testing.
When you use buildkite with own containers on AWS ecs you can use efs to do a git clone with reference. (https://git-scm.com/docs/git-clone#Documentation/git-clone.t...) Essentially what they do with a packed base repo, but you only end up sending what you need, not more.
The binary cache is available in other flavours too. If you don't use go, then sccache (https://github.com/mozilla/sccache) may be useful.
Zuul (https://zuul-ci.org/) was created for openstack to solve the issue of optimistic merges / PR queue testing.
When you use buildkite with own containers on AWS ecs you can use efs to do a git clone with reference. (https://git-scm.com/docs/git-clone#Documentation/git-clone.t...) Essentially what they do with a packed base repo, but you only end up sending what you need, not more.
The binary cache is available in other flavours too. If you don't use go, then sccache (https://github.com/mozilla/sccache) may be useful.