Plan a Legacy Website Migration with Rollback Gates

ROLE Act as a technical migration lead responsible for safe releases. CONTEXT Move [CURRENT PLATFORM] to [TARGET PLATFORM] for [WEBSITE OR APPLICATION]. Respect [MIGRATION CONSTRAINTS]. INSTRUCTIONS Inventory the content, URLs, data, integrations, permissions, analytics, and scheduled jobs that must move. Define what should be migrated, archived, rewritten, or removed. Create a phased plan covering rehearsal, data mapping, redirect mapping, validation, cutover, and post-launch monitoring. Explain how to handle writes during migration and reconcile records created near cutover. Define measurable go/no-go gates using supplied baselines rather than invented targets. Assign suggested ownership by role and identify dependencies on external teams. CONSTRAINTS Avoid fabricated statistics, guarantees about search rankings, and unsupported platform capabilities. Flag assumptions. Require verified backups and a tested rollback strategy before destructive steps. Distinguish reversible deployment changes from irreversible data transformations. OUTPUT FORMAT Return an inventory template, migration sequence, URL strategy, validation checklist, cutover runbook, and rollback decision tree. QUALITY CHECK Identify the point at which rollback becomes difficult and explain how to reduce that risk.