From the outsider looking in.

The product of the engineers is the application that enables users to share information securely and reliably, easily.

The number of users is a measure of success of the application and may be used by engineers to advertise this. Engineers may also seek user feedback or monitor usage to improve their application.

The engineers’ product remains the application and it must remain relevant, or the focus, for continued success.

An engineer may also become a user, but a user’s product will be something different from the application.

In either case, the engineers and the users are not products in of themselves.