Marc’s career spans leadership roles across sectors. He served as Director of the Dutch office of an international environmental agency and was Partner at the renowned consultancy firm Twynstra Gudde. In 2010, he co-founded WesselinkVanZijst alongside Hans van Zijst. Known for his hands-on approach, Marc is a true pracademic—blending academic insights with practical application. As a process architect and facilitator, he guides diverse groups toward constructive solutions, while simultaneously translating these experiences into SSE instruments and training programs.

Marc is the author of two books on SSE and numerous other publications. He is a respected lecturer in a variety of educational programs and a highly sought-after speaker, known for his infectious enthusiasm and engaging communication style. His dynamic presence energizes audiences and clients alike.

In his ongoing efforts to refine and disseminate the SSE concept, Marc collaborates closely with Professor Lawrence Susskind (MIT, Boston) and the Consensus Building Institute. His client portfolio includes government agencies, non-governmental organizations, and private industry, with each project approached through a lens of mutual respect and shared interests.

Marc has contributed to high-stakes complex projects such as Maasvlakte 2 (expansion of the Port of Rotterdam) and the N69/Grenscorridor, as well as interdisciplinary initiatives in nature conservation, flood protection, the energy transition and transportation infrastructure. Beyond the physical domain, he is also active in the fields of justice, public safety, and social policy.