1. A method comprising: interfacing, by a graphics export subsystem, with a graphics design subsystem to access data representative of a graphical user interface screen design; detecting, by the graphics export subsystem, a building block placeholder element in the graphical user interface screen design; accessing, by the graphics export subsystem from a repository of building block elements, data representative of a building block element associated with the building block placeholder element; and generating, by the graphics export subsystem based on the graphical user interface screen design and the building block element, computing code configured to be processed by a target computing device to render a graphical user interface screen in accordance with the graphical user interface screen design and the building block element.