Question

A logistics company runs a monolithic Java shipment-tracking application on a fleet of Compute Engine VMs. The application works but is difficult to update, and leadership wants a roadmap for incrementally modernizing it toward a microservices architecture without a risky big-bang rewrite. New features must be delivered as independent services while the existing monolith continues to serve production traffic. As the architect, which approach should you recommend for the modernization roadmap?

Accepted Answer

Apply the strangler fig pattern: place an API gateway (or HTTP(S) Load Balancer with routing) in front of the monolith and progressively route specific capabilities to new microservices while retiring the corresponding monolith code.

Answer

Freeze all new development, rewrite the entire application as microservices on GKE in a parallel project, and cut over in a single release once feature parity is achieved.

Answer

Lift and shift the monolith into a single large container and deploy it to Cloud Run so that it automatically becomes a microservices architecture.

Answer

Leave the monolith unchanged and only add new features by editing the existing codebase, deferring any architectural change until a full outage window is available.