Communication & APIs

This is what you learnYou can name mandatory fields, results and errors of a storage reservation as a contract.

In the shopOrder reserved on the contract of the storage module two cups for B-1042. The reservation has a stable identifier and an expiration date.

This is what you learnIn the checkout, you can mark which calls the order process immediately awaits a response.

In the shopIn modular monoliths, ordering requests warehouse and payment directly. The payment module calls the external payment provider via the network.

This is what you learnYou can separate acceptance, later processing and visible status of an invoice order.

In the shopAfter confirmed order, invoice accepts an order and creates the receipt later. The checkout does not have to wait for the finished PDF.

This is what you learnYou can assign queue, pub/sub and stream for three specific shop tasks.

In the shopThe shop processes invoice orders, distributes orderPaid for shipping and analysis and keeps order status changes for later evaluation.

This is what you learnYou can predict when repeated calls will trigger the same or a new business impact.

In the shopThe payment module sends B-1042 with the key pay-B-1042 to the external provider. The first answer is lost.

This is what you learnYou can show how the order and the publishing order are stored together and later shipped separately.

In the shopVariant with permanent news channel: order confirmed B-1042 and at the same time stores order confirmed in your outbox. The news channel is temporarily unreachable.

This is what you learnFor reservation and payment, you can distinguish between orchestration and choreography.

In the shopVariant: Warehouse and payment are independent services. The team compares an order orchestration with an event-driven choreography; the payment provider remains external.

This is what you learnYou can assign external shop routes to the relevant internal destinations via an API gateway.

In the shopVariant: Catalogue and shipping were separated as services for proven operational reasons. Browser and customer service access shop routes exclusively via the API gateway.

This is what you learnYou can distinguish a compatible API extension from a breaking meaning change.

In the shopThe warehouse module extends the reservation response with expiresAt. Later, the existing field available should change from a number to a business availability level.