- personal coach to DGAs at various family companies in sectors such as food retailing, care and fast-moving consumer goods
- Director at Van Gend & Loos NV, now part of DHL
- Divisional Director at NV Koninklijke Bijenkorf Beheer
- Chair of the Board of the International Division of Meco International
At Meco, Willem was involved in the sale and stock market floatation.
- Business Economics and (postdoctoral) Accountancy at the University of Amsterdam
Willem is also:
Chair of the Supervisory Board of Bake Five Holding, Leusden