When migrating applications to AWS, it doesn’t matter if you are rehosting, replatforming, or planning a full refactor—as you take each step, you should know what’s working. Above all, you need to know if the user experience of your migrated app is what you expect it to be—especially at that moment when the workload has moved and everyone is watching.
How can you tell that a migration has successfully completed? How can you be sure that you haven’t introduced a problem or a looming concern into your application? How do you determine that you don’t need to do any further tuning or adjusting to ensure that your app that was previously running fine on-premises is stable and performing well in the cloud?
Ultimately, you can’t declare a migration successful until you’ve proven it works as expected in the new environment.