This study investigated psychological and behavioral factors influencing university students’ career decision-making in the Fourth Industrial Revolution and post-COVID-19 era. It examined the effect of grit and the multiple mediation effects of SNS competence, class attitude, major satisfaction, and self-leadership. Data from 253 undergraduates in G Metropolitan City were analyzed using SPSS 24.0 and Process Macro Model 6. Results showed grit significantly affected career decision level, with SNS competence, class attitude, and self-leadership acting as significant mediators in serial paths. Major satisfaction was not significant. These findings highlight the importance of digital literacy and self-directed abilities for better career decisions and offer practical implications for career guidance.