As job markets worldwide have become more competitive and applicant selection criteria have become more opaque, and different (and sometimes contradictory) information and advice is available for job seekers wishing to progress in their careers, it has never been more difficult to determine which factors in a résumé most effectively help career progression. In this work we present a novel, large scale dataset of over half a million résumés with preliminary analysis to begin to answer empirically which factors help or hurt people wishing to transition to more senior roles as they progress in their career. We find that previous experience forms the most important factor, outweighing other aspects of human capital, and find which language factors in a résumé have significant effects. This lays the groundwork for future inquiry in career trajectories using large scale data analysis and natural language processing techniques.