Software Architect's Handbook

Refactor (or re-architect)

When refactoring an application for a cloud migration, you are making modifications to the application, possibly including its architecture. You may be refactoring the application to take advantage of the cloud-native features available in its new environment.

Legacy applications that are refactored properly will have greater availability, improved scalability, and faster performance. In addition to these advantages, an organization can realize cost benefits after the application has been migrated. The refactoring/re-architecting approach can potentially be quite involved though. Depending on what needs to be done, the migration process itself may take longer and cost more to execute.