In this scenario, Salesforce acts as the trigger for a business process that completes in an external system. The architect's recommendation for the remote system to subscribe to a platform event is the classic implementation of the Remote Process Invocation—Fire and Forget pattern.1

In a Fire and Forget pattern, Salesforce initiates a process by publishing a message (the event) to the event bus and then immediately continues its own2 processing without waiting for a functional response from the target system. The "Fire" part occurs when the order details are captured and the event is published; the "Forget" part refers to Salesforce handing off the responsibility of order creation to the remote system. This pattern is ideal for improving user experience and system performance, as it avoids blocking the user interface while waiting for potentially slow back-office systems to respond.

Option A (Request and Reply) is incorrect because that would require Salesforce to make a synchronous call and wait for the remote system to confirm the order was created before allowing the user to proceed. Option C (Remote Call-In) is the inverse of what is described; it would involve the remote system actively reaching into Salesforce to "pull" the data, whereas here Salesforce is "pushing" the notification via an event stream. By using Platform Events to facilitate this hand-off, Northern Trail Outfitters ensures a decoupled, scalable architecture where the remote system can process orders at its own pace while Salesforce remains responsive to sales users.