Background

Launch is flip. This task covers the pre-launch checklist to catch problems early.

Goal

Experiment running in production at target traffic split, with monitoring live and a documented rollback plan.

Requirements

• All prior sub-tasks complete and signed off before launch proceeds.
• Rollback plan documented: kill switch? with what threshold?
• Monitoring in place for error rates, and event pipeline health.
• Confirm Data Engineering pipeline is receiving events from production before increasing traffic.

Rollback plan:

1. Hiding donor badge (container) overall with !important
2. TestKitchen: https://wikitech.wikimedia.org/wiki/Test_Kitchen/Conduct_an_experiment#Emergency_shutdown

Acceptance Criteria for Done

• Pre-launch checklist completed and signed off by experiment owner and supporting engineers.
  • Backporting remaining patches
    • ✅ Donor Delight Badge: Unify on "Remove badge" language across treatments (mediawiki/extensions/WikimediaCustomizations~1300186) for better i18n
    • ✅ A11y Donor Badge: Remove Badge button disappears too quickly (mediawiki/extensions/WikimediaCustomizations~1300228)
    • ✅ Donor Delight Badge, styles: Amending to final design review feedback (mediawiki/extensions/WikimediaCustomizations~1300171)
• Manually turn on at experiment overview in TestKitchen (beyond just setting starting/end date) before experiment deployment window 14:30-15:00 UTC
• Experiment live in production at initial traffic split.
• Event pipeline confirmed receiving data from production.
• Monitoring live.
• Rollback plan documented.
• Experiment end date set in TestKitchen.

Communications

• List experiment in https://meta.wikimedia.org/wiki/List_of_experiments_in_Product_and_Technology
• Make release announcement in internal #release-and-sunset-announcements Slack channel