What does a system architect create when setting up a portal?

In the context of setting up a portal, the creation of an application overlay is essential. An application overlay refers to a customized interface that allows users to access specific features or components of an application through a streamlined and user-friendly design. This overlay ensures that the portal is tailored to meet the needs of its users, facilitating ease of access to the necessary functionalities while potentially improving user experience.

Focusing on the other options, role management typically involves defining the permissions and responsibilities of users within the portal, but it does not directly pertain to the visual or interactive setup of the portal itself. Access control relates to the mechanisms that regulate who can view or interact with different parts of the application, which is a different consideration from the physical layout and presentation of the portal. Lastly, the configuration module is used for managing settings and preferences within the application but does not specifically involve the creation of a user-facing portal structure. Thus, the application overlay stands out as the primary component created when establishing a portal.