## Summary Roll out [view transitions](https://gitlab.com/gitlab-org/gitlab/-/work_items/613948) currently behind the `view_transitions` feature flag. - DRI: @thutterer - Team Slack channel: `#g_design_expression_internal` > [!note] > Process and guidance live in the docs — this issue is just the commands and a place to track the rollout. > "Rolling out" means incrementally enabling the flag on GitLab.com to validate stability — it is not the same as releasing the feature, which happens when the flag is removed. > [Feature flag controls](https://docs.gitlab.com/development/feature_flags/controls/) · [Feature flag lifecycle](https://handbook.gitlab.com/handbook/product-development/how-we-work/product-development-flow/feature-flag-lifecycle/#feature-flag-lifecycle) ## What could go wrong? - **Render-blocking `super_sidebar.js`.** The main risk. Making the bundle `blocking: 'render'` delays first paint until it loads and executes. If the bundle is slow, large, or fails to load (CDN hiccup, cache miss, chunk error), users could see a blank page longer than today or, worst case, a page that never paints. Watch first-paint / LCP and error rates during rollout. - **Browser support.** View transitions only work in Chromium and Safari. Firefox and older browsers just get normal navigation. No transition, no regression expected. But the render-blocking change applies to *all* browsers, so any first-paint regression is not limited to view-transition-capable ones. - **Blank/flashing transitions.** The AI rail (right side, from `main.js`) is not covered, so it may still flash or pop in mid-transition. Long-running navigations could also show a frozen snapshot of the old page while the new one loads. - **Reduced-motion users** are excluded via `prefers-reduced-motion`, so no accessibility regression is expected, but confirm the media query actually suppresses the animation. - **Rollback:** disabling the `view_transitions` flag fully reverts both the CSS and the render-blocking behavior, with no data migration or cleanup needed. ## Rollout Run all production `/chatops` in [`#production`](https://gitlab.slack.com/archives/C101F3796) and cross-post the results to `#<slack-channel-of-dri-team>`. Background: [incremental rollout process](https://docs.gitlab.com/development/feature_flags/controls/#process), [feature actors](https://docs.gitlab.com/development/feature_flags/#feature-actors). **Non-production** ``` /chatops gitlab run feature set <feature-flag-name> 50 --actors --dev --pre --staging --staging-ref /chatops gitlab run feature set <feature-flag-name> true --dev --pre --staging --staging-ref ``` **Production** — percentage rollout (wait ≥15 min between steps, watch dashboards): ``` /chatops gitlab run feature set <feature-flag-name> <percentage> --actors ``` Or target specific actors instead: ``` /chatops gitlab run feature set --project=gitlab-org/gitlab,gitlab-org/gitlab-foss <feature-flag-name> true /chatops gitlab run feature set --group=gitlab-org,gitlab-com <feature-flag-name> true /chatops gitlab run feature set --user=<gitlab-username-of-dri> <feature-flag-name> true ``` ## Before global rollout Confirm the relevant gotchas before going to 100% — see [enabling a feature for GitLab.com](https://docs.gitlab.com/development/feature_flags/controls/#enabling-a-feature-for-gitlabcom): - [Docs + version history](https://docs.gitlab.com/development/documentation/feature_flags/) updated - [Breaking changes](https://docs.gitlab.com/development/documentation/release_notes/#deprecations-removals-and-breaking-changes) announced, if any - [Change management issue](https://handbook.gitlab.com/handbook/engineering/infrastructure-platforms/change-management/#feature-flags-and-the-change-management-process) opened, if required - [External API consumers](https://docs.gitlab.com/development/feature_flags/#do-not-use-feature-flags-in-external-api-consumers) handled with a fail-open mechanism, if applicable ## Cleanup Remove the flag once [deemed stable](https://handbook.gitlab.com/handbook/product-development/how-we-work/product-development-flow/feature-flag-lifecycle/#feature-flag-lifecycle) — see [cleaning up](https://docs.gitlab.com/development/feature_flags/controls/#cleaning-up). Track it here, or open a follow-up [Feature Flag Cleanup issue](https://gitlab.com/gitlab-org/gitlab/-/work_items/new?description_template=Feature%20Flag%20Cleanup). Remove the flag and its YAML definition from the codebase, then: ``` /chatops gitlab run release check <merge-request-url> <milestone> /chatops gitlab run feature delete <feature-flag-name> --dev --pre --staging --staging-ref --production ``` ## Rollback ``` /chatops gitlab run feature set <feature-flag-name> false # production /chatops gitlab run feature set <feature-flag-name> false --dev --pre --staging --staging-ref # non-production /chatops gitlab run feature delete <feature-flag-name> --dev --pre --staging --staging-ref --production # remove entirely ```