Question

A retail company runs a legacy customer loyalty application on-premises. It consists of a Windows-based web front end, a proprietary rules engine licensed per-CPU from a vendor, and a SQL Server database. The company wants to migrate to AWS within 4 months. Analysis shows the rules engine vendor now offers an equivalent SaaS subscription with a public API, which would eliminate the per-CPU licensing costs and ongoing patching burden. The web front end and database are actively maintained by internal developers and must remain under the company's control. Which combination of migration strategies best minimizes long-term operational cost and risk?

Accepted Answer

Repurchase the rules engine by adopting the vendor SaaS subscription, and replatform the web tier and database to AWS (for example, EC2/containers and Amazon RDS for SQL Server).

Answer

Rehost the entire application stack (web tier, rules engine, and database) to EC2 using AWS Application Migration Service to meet the deadline fastest.

Answer

Refactor all three components into serverless microservices using Lambda and Amazon Aurora to fully modernize the application.

Answer

Retain the rules engine on-premises with a Direct Connect link, and rehost only the web tier and database to EC2.