What should the architect do to ensure a newly added Salesforce object will integrate with the existing financial system?

To ensure that a newly added Salesforce object can properly integrate with an existing financial system, downloading the latest enterprise WSDL is the most appropriate action. The enterprise WSDL is tailored for Salesforce's object model and includes all the necessary definitions and structures specific to your Salesforce environment, including any new objects or changes.

Using the enterprise WSDL enables the integration to access the most up-to-date schema details and operations related to the new object, ensuring that the financial system can accurately communicate with Salesforce. This is crucial for maintaining data integrity and seamless functionality between the two systems.

In contrast, the partner WSDL offers a more generic layout that is less tailored to specific Salesforce instances. While it may still be useful for some integrations, it doesn't provide the same level of detail regarding custom objects and fields as the enterprise WSDL. Transitioning to the partner WSDL or metadata API might limit the integration capabilities or complicate the process since they may not reflect the precise current object definitions required for effective data communication.