She held a wide variety of positions, but spent most of her career as a director of an investigation bureau. In this capacity, she made assessments of the functioning and the financial situation of private companies. Mrs. Mahieu also worked as an interim-manager and consultant in retailing, where she made performance assessments and gave tailored advice on business improvement. In her current role as office manager, she carries out a broad range of organizational and administrative activities that facilitate the smooth running of HCSS’s day-to-day business. Mrs. Mahieu has also acted as a board member of the EJ Esther Foundation, which promotes the cultural diversity of The Hague by initiating and supporting cultural events and art exhibitions.