This issue is to track gitlab-ce~4107678 improvements for ~CI in gitlab-ce~3011727 that improves overall performance. ## Related - [ ] Optimise build picking: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/9511, - [x] Persist stages in database: https://gitlab.com/gitlab-org/gitlab-ce/issues/26481, - [ ] Show persisted stages in the UI instead of calculating that on the fly. - [x] Store information about retry in database: https://gitlab.com/gitlab-org/gitlab-ce/issues/25737, - [x] Deprecate old runners: https://gitlab.com/gitlab-com/infrastructure/issues/1303, - [x] Optimise pipelines json: https://gitlab.com/gitlab-org/gitlab-ce/issues/27377, - [ ] Update pipeline status synchronously: https://gitlab.com/gitlab-org/gitlab-ce/issues/23257, - [ ] Improve support for handling big pipelines, (additional issues will be added once we figure out them)