This chapter explains the unresolved debate on how careers of individuals are constructed and shaped, and how or why they do change and evolve over time. It focuses on the question whether and to what extent structure and agency are interwoven in a way that allows acknowledging that careers are outcomes of both structural and agentic forces. The chapter explores how careers may be dependent on contextual developments but also how they feed back to the context. Most of the literature on careers indicates that structure and agency are separate entities, which get divided from and studied in isolation of one another. The realist approach argues for moving beyond positivist or rationalist notions of agency and accounting for deep structures shaping conduct, such as past events and experiences, or structures of power and domination. Structuration theory provides both a theoretical and a methodological approach for connecting structure and agency.