Customer State Transfer

The Customer module has not been the focus of much reworking in the past but, like Store Management, it maintains a resource that is of interest to the other modules: the customer data.

Transferring the state but not the responsibility

A quick word of caution about the customer and other shared state in an event-driven application: when we transfer state with events, we do not transfer domain responsibilities along with it.

If the module or service that owns the customer data is also responsible for authorization or authentication, that responsibility stays with it, and it must continue to be called to perform that function.