This article provides guidance on achieving successful testing and cutover using AWS Application Migration Service for server migrations to AWS.

• Identify dependencies on shared services like Active Directory and backup servers before testing
• Test instances have same names as production servers; verify correct instance before making changes
• Prevent test instances from processing production data queues or files to avoid data loss
• Disable dynamic DNS registration on Windows servers to prevent test instances overwriting production DNS
• Use isolated sandbox VPCs to segregate test environments from production infrastructure
• Replicate Active Directory domain controllers into sandbox for proper server functionality
• Test firewall rules and third-party connectivity using blank EC2 instances before cutover
• Implement automated and synthetic testing to validate end-to-end business processes
• Stop all services on source servers before final replication to ensure data consistency
• Replace on-premise backup and monitoring agents with AWS-native services to reduce costs
• Coordinate with security and compliance teams on AMI approval requirements early

Proper testing planning, sandbox isolation, and automated validation help ensure smooth migrations while avoiding common pitfalls like DNS conflicts and data inconsistencies.