This study addresses the impact of evolving organizational dynamics on career paradigms, focusing on protean careers in the context of boundaryless trajectories. Framed within social cognitive career theory, we investigate how protean career orientation, perceived self-efficacy, and managerial competencies acquired at higher education influence subjective career success. Employing a two-wave research design over three consecutive years, we collected data through two online questionnaires, the second one 9-12 months after the first survey. We tested our research model via structural equation modelling (SEM) and path modelling techniques, applying AMOS and the PROCES macro tool. Our findings based on 217 participating management alumni reveal that early career conditions, particularly self-efficacy and protean career orientations, predict subjective career success. A moderated mediation analysis indicates that a high perception of managerial competencies enhances the effect of self-efficacy on career success through protean career orientation. This study builds on existing research by investigating how formal knowledge acquired at university contributes to future career success. It underscores the importance of proactive individuals with a protean orientation and heightened career self-efficacy, providing theoretical insights and practical implications for predictors of career success.