The integration architect should consider whether the fulfillment system can make a callback into Salesforce and whether it can implement a contract-first Outbound Messaging interface. A callback is a wayfor the fulfillment system to send a response or an acknowledgment back to Salesforce after receiving an order1. This can help ensure data consistencyand reliability between the two systems. A contract-first Outbound Messaging interface is an approach where the integration is designed based on a predefined XML schema that defines the structure and content of the messages2. This can help ensure interoperability and compatibility between the two systems. The other two questions are not relevant for the integration architect to consider. The fulfillment system does not need to create new addresses within the Order Create service, as this is a function of Salesforce3. The product catalog data does not need to be identical at all times in both systems, as long as there is a mapping or synchronization mechanism to handle any discrepancies