What is entrepreneurship and what makes an entrepreneur? While the founding of highly innovative firms with significant growth potential forms the cornerstone of economic growth, the labour market at large is increasingly being populated by self-employed contract workers. Understanding the social histories of these two populations – where they come from, what they do, how they refer to themselves and why they succeed or fail – is important not just to the academic field of entrepreneurship, but also to informed policy making and resource allocation. I study the socio-economic and career factors that affect both high potential start-up founding and self-employment outcomes. I address these questions through the computational analyses of start-up data repositories (e.g. PitchBook, CrunchBase, AngelList) and a hand-collected dataset of over 3 million unstructured resumes that comprise the high-technology professional ecology of the US.