Three levels from middleware concepts, communication models, JMS, API gateways, SOA, and platform overviews through enterprise messaging, Kafka, web services, API management, ESB concepts, OAuth/JWT, distributed transactions, and cloud-native integration, into distributed protocols, ESB design, EDA, service mesh, performance tuning, governance, observability, sagas, and a capstone review. Format: Theory + Lab/Assignments per syllabus.