Over a career in research and policy, José Siri has developed and applied systems approaches to urban and planetary health, focusing on leveraging science for healthy development, devising simple systems tools to catalyze better decision-making, and improving understanding of complex challenges. His experience, which spans five continents, includes time at the International Institute for Applied Systems Analysis, the United Nations University International Institute for Global Health, and the Wellcome Trust, and extensive engagement with researchers, practitioners, and policymakers. He has published over 30 peer-reviewed articles and book chapters, along with policy briefs and commentaries in publications ranging from the Wall Street Journal to the Global Sustainable Development Report. He currently consults for the World Bank and the World Health Organization and holds advisory roles with the Inter-American Institute for Global Change Research, Future Earth, CDP, and a variety of urban and planetary health research projects. His work has touched on urban studies, climate and health, sustainable development, systems thinking, transdisciplinarity, epidemiology, ecology, infectious disease, public health, and malaria control.