Reimagining education for sustainability: insights from Indonesia’s largest project-based learning program

Purpose Global challenges such as climate change, economic inequality, and social injustice require higher education to prepare future leaders with sustainability-oriented problem-solving competencies. While project-based learning (PBL) is often promoted for this purpose, how diversity within student teams enables the development of sustainability competencies remains underexplored. Design/methodology/approach This study examines survey data from 16,824 Indonesian undergraduates participating in the Certified Internship and Independent Study (MSIB) program, a nationwide PBL initiative involving placements across 349 companies. Findings In PBL settings, effective communication skills, cognitive diversity and problem-solving skills interact to shape sustainability competence development. Cognitive diversity strengthened the association between communication and problem-solving, indicating that team composition shapes how communication translates into problem-solving in large-scale experiential programs. Nevertheless, the conditional indirect effect did not significantly vary across levels of cognitive diversity. Originality/value Using a nationwide survey from one of the world’s largest internship-based PBL programs, this study tests an integrative framework linking communication, problem-solving and cognitive diversity to sustainability competence. The findings show that cognitive diversity strengthens the communication–problem-solving relationship, indicating first-stage moderation rather than moderated mediation.