David Sim is a Scottish architect and urban planner who specializes in creating people-centered cities. He is the creative director of Gehl Architects, where he works on projects that improve the quality of urban life. Seven promotes the concept of "soft" cities, where the density of buildings promotes comfortable interaction and social activity. His book "The Soft City. Building Density for Everyday Life" focuses on the importance of humanity in urban planning, offering approaches to creating friendly and livable spaces.