What is the primary difference between lift-and-shift (rehost) and re-architecture (refactor) migration strategies?

• A. Rehost moves workloads with minimal changes; refactor modifies code to leverage cloud-native services for improved scale and cost.
• B. Rehost moves to cloud-native services; refactor uses on-premises resources.
• C. Refactor is always faster than rehost.
• D. Both require no changes.

Answer: (A)

The difference being tested is how much you change the application when moving to the cloud. Lift-and-shift (rehost) means moving workloads with minimal changes, preserving the existing architecture, code, and configurations as much as possible so the migration is quick. Re-architecture (refactor) means redesigning or modifying the application's code and design to take advantage of cloud-native services—like managed databases, serverless components, and autoscaling—to improve scalability and potentially reduce costs.

For example, moving a virtual machine-based web app to the cloud with the same stack is lift-and-shift. Re-architecting would involve replacing self-managed components with managed services (such as switching to a managed database, adding serverless functions, or decomposing the app into microservices) to better exploit cloud capabilities.

The other statements don’t fit because lift-and-shift is not about moving to cloud-native services, rehost is not about using on-prem resources, refactoring isn’t inherently faster, and both strategies usually require some changes to achieve their goals.