Let's pull this all together with an end-to-end example of a typical ordering process of an e-commerce system. At the highest level, the system receives an order, forwards the order to a third-party order-management system, and receives order status updates. The system is built using our cloud-native patterns.
We have a frontend (FE) application that submits orders to its BFF component. The BFF component emits the order-submitted event type and consumes the order-received and order-fulfilled event types to track the order status. These two pieces are owned by the same team. Another team owns the external service gateway (ESG) component that encapsulates the interactions with the third-party order management system. This component consumes the fulfill-order event type and emits fulfill-order-received and fulfill-order-complete event types...