.NET multi-tenancy: move a tenant without downtime — part 4/4

This installment explains how to move a tenant from a shared database to a dedicated one without taking the application offline or disrupting other tenants. The catalog drives the switch, while the same EF Core model and query filter serve both isolation modes.

The migration uses an initial copy, a temporary read-only window, a delta copy, and verification before cutover. The runbook waits for the cache to expire before reopening writes, preventing instances that still hold the old connection from writing to the shared database after the switch.