Our client, using our services, had previously migrated their core production application to AWS. This project dealt with their corporate systems (including active directory, user file shares, etc) and migrating them to AWS as well as integrating with AWS services.
The approach we took was to identify how to migrate their services into native AWS solutions or extend on top of them. AWS native support for VMWare expedited the process of migrating their VMWare VMs into AWS. We used amazon native services, such as Amazon Cloud Directory and AWS Storage Gateway, to migrate their user databases and file shares.