Jan Willem Rosenboom is a senior program officer in the Water, Sanitation and Hygiene Strategy for the Bill & Melinda Gates Foundation, based in Seattle. He is a public health engineer who has been fascinated by water and sanitation for many (many) years. At the foundation, he manages a substantial grant portfolio including investments in market research and market making, policy development, business model development, scaled sanitation service delivery and low-cost sanitation product development.