SOA

Service-Oriented Architecture emphasizes coarse-grained services, shared contracts, enterprise buses, and governance across heterogeneous systems. It predates cloud-native microservices but remains relevant in legacy integration, ESB discussions, and regulated environments with strict interface control.

On interviews: contrast SOA enterprise bus thinking with fine-grained microservices. Explain when shared canonical models help versus harm autonomy.

Common pitfalls: treating SOA as only XML web services; central ESB becoming a bottleneck; canonical data models that ignore bounded context differences.

Checklist:

• Know ESB versus point-to-point trade-offs.
• Align service contracts with business capabilities.
• Governance includes deprecation and compatibility policy.
• Distinguish SOA from microservices hype cleanly.