Background: The ability to adjust to career transitions is becoming increasingly important because of rapid technological developments, which alter labour markets and workplace demands. Objectives: Within the framework of the career construction model of adaptation, we examined the relationships among core self-evaluation (adaptivity readiness), career adaptability (adaptability resources), and subjective career success (adaptation result). Methods: For this purpose, we used structural equation modelling (SEM), a cross-sectional design and sampled 242 employees from a higher education institution in South Africa. Results: The results showed that core self-evaluation is a powerful and reliable predictor of subjective job success across the eight categories. The growth and development subdimension was significantly impacted by career adaptability, but the impact on subjective career success was lower than expected. Conclusion: We found that psychological resources, especially core self-evaluation qualities such as emotional stability, self-efficacy and self-esteem, influence employees’ views of purposeful and a happy workplace. We recommend that adaptive readiness be developed through person-centred interventions or psychological therapies for boosting resilience and job satisfaction. By shifting the focus to internal psychological resources influencing career outcomes, especially in the context of higher education in South Africa, the study makes a theoretical and a practical contribution to career development literature. Recommendations for future research include exploring behavioural responses and longitudinal dynamics of career adaptation. Contribution: This study extends the career construction model by empirically validating the mediating role of career adaptability between core self-evaluation and subjective career success. It contributes to the understanding of how internal psychological resources shape adaptive career outcomes in higher education, offering evidence-based guidance for employee development and organisational career interventions.