This research aims to study and analyze the effects of human resource flexibility, employee competencies, organizational culture adaptation, and job satisfaction on employee performance. The study also examines the indirect effect between human resource flexibility and employee performance with the mediation of organizational culture adaptation and the effect of competence on employee performance through job satisfaction as a mediator variable. Us-ing certain criteria, 105 employees of PT Pos Indonesia were selected as the sample. SEM-PLS was used to test the hypotheses. The study finds that human resource flexibility, employee competencies, and job satisfaction significantly influenced employee performance, but organizational culture adaptation did not have any significant effect on employee performance. Therefore, organizational culture adaptation was unable to mediate the effect of human re-source flexibility on employee performance. However, job satisfaction partially mediates the effect of employee competencies on employee performance.