Attrition in surgical training, a result of poor well-being at work, continues to rise. Work engagement and persistence, the other side of the coin, depend on the proactivity of residents to optimize the demands and resources in the workplace to achieve a better fit with the environment. This type of proactivity refers to job-crafting. In this study, we sought to explore the specific mechanisms underlying residents' job-crafting to enhance work engagement and persistence, as well as the role of supervisors in this endeavor.We used a constructivist-grounded theory design. We conducted semistructured interviews of active residents. During the analysis of verbatim protocols, we developed codes and categories and identified the main themes (job-crafting mechanisms) related to work engagement and persistence. We anticipated procedures to engage in reflexivity.The residents showed six job-crafting mechanisms (build trust with supervisors, manage proactively, seek help, see errors and frustrations as learning opportunities, find a suitable work-life balance, and seek challenges actively). The supervisors contributed to residents' job-crafting with four mechanisms (earning the trust of the residents, providing guidance and support, allowing residents to fulfill tasks befitting a surgeon in training, and offering increasingly challenging tasks to residents).Work engagement and persistence in training are active processes that depend on the ability of residents to take advantage of resources and challenges and to diminish hindering demands at the workplace. Future research should focus on the perspectives of the supervisor, as well as on the effectiveness of job-crafting interventions, to enhance work engagement.