An interface enables a user to select a graphical object to include in a flow. The graphical object is associated with code, and this code may relate to presenting digital content. The interface further allows a user to define a graphical relationship in the flow, such as a connection between the graphical object and another element of the flow. The interface may present the flow in a first area of a display and the digital content in a second area of the display. The code may be executed based on the graphical relationship. For example, the graphical relationship may indicate an order for executing code sections associated with the flow and data exchanged within the code sections.