What approach should be taken to update case status in the legacy system after closing in Service Cloud?

Using outbound messages for status updates is an effective approach due to the nature of how communication between systems is structured in integration scenarios. Outbound messaging is part of Salesforce's platform and allows for automated, secure communication between Salesforce and external systems without requiring extensive coding or real-time sync complexity.

When a case is closed in Service Cloud, an outbound message can be triggered to the legacy system, informing it of the status change. This messaging approach adheres to a more decoupled architecture, allowing the legacy system to receive updates asynchronously. It enhances reliability because the system does not need to wait for a real-time response, which can be affected by network issues or other delays.

Additionally, outbound messaging is integrated into Salesforce workflow rules, making it a straightforward way to set up the necessary logic without extra overhead. This method supports key integration principles by ensuring the systems are loosely coupled, promoting better scalability and maintainability over time.

While other options involve direct calls or middleware solutions, they might introduce complexities such as handling immediate responses and maintaining session states, which outbound messages successfully mitigate.