DR strategies: backup-restore (high RPO/RTO), pilot light (minimal standby), warm standby (scaled for partial load), multi-site active-active.
RTO (Recovery Time Objective) — acceptable downtime. RPO (Recovery Point Objective) — acceptable data loss. Inverse relationship: higher availability costs more.
Implementation: Aurora Global Database (cross-region replication), DMS continuous replication, backup automation, traffic failover via Route 53. Runbooks and automation reduce manual recovery time.