Purpose: Informed by the job characteristics model (JCM) and job crafting theory (JCT), this study aims to investigate the mediating role of meaningfulness at work in the relationship between a growth mindset and in-role performance and moderating role of job crafting in this indirect effect. Design/methodology/approach: To this end, the authors examined the moderated mediation model with 271 corporate trainers enrolled in the largest online community for adult educators in South Korea. Findings: Results showed that the relationship between a growth mindset and in-role performance is positively mediated by meaningfulness at work. Furthermore, job crafting acted as a moderator in this relationship, such that trainers with high levels of job crafting showed a greater in-role performance, while trainers with low levels of job crafting reported a negative indirect effect of a growth mindset. Originality/value :The current study contributes to the JCM and JCT by suggesting a growth mindset as individual characteristics to promote meaningfulness at work and in-role performance. The study also responds to the calls to expand the mediation mechanisms and boundary conditions of a growth mindset in the workplace. The authors provide important insights into how corporate trainers' job crafting is crucial in enhancing or impeding their performance and meaningful work.