A retailer must exit its datacenter in 12 weeks. Its core Java EE monolith runs on WebSphere and uses an Oracle database with many PL/SQL packages. Testing capacity is limited; the business requires feature parity on day one. A broader modernization to microservices on containers is planned for next year. What migration approach should you recommend now?

Lift-and-shift (rehost) is the best option given the tight 12-week deadline, limited testing, and the need for immediate feature parity. Rehosting the existing WebSphere and Oracle setup on Azure VMs minimizes changes, reducing risk and accelerating migration. This approach allows the retailer to meet the datacenter exit deadline while deferring complex re-architecture until next year, as planned. Re-platforming to Azure App Service and Azure SQL Managed Instance would require significant refactoring and testing due to the shift from WebSphere/Java EE to Java SE and Oracle PL/SQL to SQL Server T-SQL, which is too complex for the given timeline and testing constraints. Re-architecting to microservices on AKS and Cosmos DB is a major undertaking, far exceeding the 12-week window and the immediate goal of feature parity. Replacing with SaaS is not feasible as it implies a completely new system, which would not provide feature parity on day one and would require extensive data migration and user training, also impossible within 12 weeks.