Hans has been involved in sustainable development since 1995 and a solid track record in producer development, roundtables and certification. Hans started working after his career as an investment officer for Triodos Bank in The Netherlands where he developed the sustainable investment service of the bank. In 1999 he came in contact with coffee farmers in Guatemala who were developing a new form of certification with main stream coffee buyers and roasters. He joined the Guatemalan farmers as a special project manager responsible for implementing certification and transfer of ownership. In 2001 he joined Solidaridad and developed the coffee and cocoa programme and served as a board member of Utz Certified from 2001 until 2008. In 2010 Hans founded Solidaridad in West Africa, running programs in Ghana, Mali, Ivory Coast, Nigeria and Cameroon on cocoa, oil palm, cotton and gold. In 2013 Hans returned to Solidaridad in The Netherlands.