What are the key considerations for validating data integrity and application performance after completing a large scale database or application migration?

Post migration validation typically involves running automated row count and checksum comparisons between the source and target databases to confirm data integrity, performing thorough functional and performance testing of the migrated application under realistic load, closely monitoring the new environment using CloudWatch for any unexpected errors or performance regressions, and maintaining the ability to roll back to the original environment for a defined period in case unexpected issues surface only after real production traffic begins flowing to the new environment.

aws dms describe-table-statistics --replication-task-arn arn:aws:dms:us-east-1:123456789012:task:my-task