Integrations can follow multiple different patterns and have different requirements.

API first is a modern approach where developers can agree on a definition, create test mockups, share documentation and then start developing. Infrastructure teams can then define security boundaries and protocols, throttling and business can track consumptions and enter into monetization scenarios.

Mediated and orchestrated services, typically synchronous and stateless, are provided by a service bus. End to end traceability, auditing, and very high performance are typical requirements for this layer.

Long running transaction is provided by process engines that handle persistence, asynchronous services, file processing and more complex business logic.

Messaging using Kafka and similar solutions provide high performance event-based integrations, and act as foundation for micro services choreographies.