The era of Big Data brings with it the need to develop new skills for managing this heterogenous, complex, large scale knowledge source, to extract its content for effective task completion and informed decision-making. Defining these skills and mapping them to demand is a first step in meeting this challenge. We discuss the outcomes of visual exploratory analysis of demand for Data Sci- entists in the EU, examining skill distribution across key industrial sectors and geolocation for two snapshots in time. Our aim is to translate the picture of skill capacity into a formal specification of user, task and data requirements for de- mand analysis. The knowledge thus obtained will be fed into the development of context-sensitive learning resources to fill the skill gaps recognised