We’re considering moving a production database from AWS RDS to Azure SQL, and the application cannot be offline for a long maintenance window. The database is large enough that a simple export and import would take longer than we can comfortably allow.

For teams that have handled a similar cross-cloud database migration, what parts took the most planning: keeping data in sync, handling schema differences, or switching application connections? I’m trying to understand what migration approach fits this kind of downtime constraint.