This article uses different career development theories as lenses to analyse the cases of four young adults who struggle to build sustainable careers and, vice versa, explores the contribution of each theory to understanding career agency as it does or does not manifest within the cases. A key element of this study is incorporating Vygotsky's theory of double stimulation (DS), initially developed as a research methodology, guiding principle, and model for agency within cultural-historical activity theory, as a lens in career research. The analyses resulted in a comprehensive model integrating theoretical and empirical insights about stalling career agency.