We're building some similar tech at GitLab, though without the dependency analysis yet. Merge Requests now combine the source and target branches before buildi

We're building some similar tech at GitLab, though without the dependency analysis yet. Merge Requests now combine the source and target branches before building, as an optimization: https://docs.gitlab.com/ee/ci/merge_request_pipelines/#combined-ref-pipelines-premium https://docs.gitlab.com/ee/ci/merge_request_pipelines/#combi... Next step is to add queueing (https://gitlab.com/gitlab-org/gitlab-ee/issues/9186 https://gitlab.com/gitlab-org/gitlab-ee/issues/9186), then we're going to optimistically (and in parallel) run the subsequent pipelines in the queue: https://gitlab.com/gitlab-org/gitlab-ee/issues/11222 https://gitlab.com/gitlab-org/gitlab-ee/issues/11222. At this point it may make sense to look at dependency analysis and more intelligent ordering, though we're seeing nice improvements based on tests so far, and there's something to be said for simplicity if it works.