Question

A retail company runs a large Java monolith on-premises that handles product catalog, order processing, and inventory management. Leadership wants to migrate to AWS and gradually modernize toward microservices, but they cannot afford a big-bang rewrite due to business risk. They want to move to AWS quickly, then incrementally extract high-value functions (starting with the order processing module) into independent services without disrupting the still-running monolith. Which approach best balances migration speed with progressive modernization and risk reduction?

Accepted Answer

Rehost the entire monolith to EC2 using AWS MGN, then apply the strangler fig pattern—placing an API Gateway or ALB in front to route specific paths (e.g., order processing) to newly built microservices while the monolith continues to serve remaining routes.

Answer

Refactor the entire application into microservices on ECS before any migration, then cut over to AWS in a single deployment once all services are complete and tested.

Answer

Replatform the monolith into a single large container on ECS Fargate and scale it horizontally, deferring any decomposition into microservices indefinitely.

Answer

Repurchase a SaaS commerce platform to replace the monolith entirely, migrating all data with AWS DMS and decommissioning the custom application.