This chapter explains how a contest platform can support different stakeholders prior to, during, and after the contest. First, the notion of a contest platform is described. This is followed by a description of the activity, followed by running examples that guide the organiser to select and develop a suitable contest platform. Develop contest platform is affected by the contest design, but also affects which stakeholders to engage in the pre-contest phase. The notion of a platform has several meanings, as we explore in the Read More section concluding this chapter.