System design · Advanced · 45 min

Migrate a live reporting dataset

Connect a consistent snapshot to ongoing changes without losing records.

Task

Move a reporting dataset from a transactional source to a new warehouse while writes continue. Updates and deletes must survive the move. Readers need a consistent result and a reversible cutover; matching row counts alone is not sufficient evidence.

Requirements

Define the snapshot/change-stream boundary and retained log position.
Handle retries, out-of-order versions, deletes, and schema differences.
Reconcile normalized records and explain acceptable lag and mismatch thresholds.
Show reader cutover, ownership of writes, rollback limits, and monitoring.

CDCMigrationReconciliationCutover and recovery

Loading exercise…