How do you implement disaster recovery for a critical application?

DR implementation: 1) Define RTO/RPO requirements, 2) Use Multi-AZ deployments for high availability, 3) Implement cross-region backups, 4) Use Route 53 health checks for failover, 5) Automate infrastructure with CloudFormation, 6) Regular DR testing and documentation, 7) Consider pilot light or warm standby based on requirements.