As cities face mounting pressures from aging infrastructure, climate change, and social inequities, new approaches are needed to design resilient, sustainable, and equitable urban systems. This book introduces a powerful, step-by-step methodology for conceptualizing and managing complex infrastructure projects through the unique lens of systems architecture, showing how this approach supports better decision-making, transparency, and collaboration. Drawing on real-world examples, the book explores concepts including trade-offs, stakeholder needs, and system interdependencies. It demonstrates how to integrate qualitative and quantitative factors, navigate uncertainty, and reason across diverse disciplines and timescales. Crucially, this book offers long-awaited solutions for bridging the technical and social demands of urban infrastructure design. By extending systems architecture into the urban domain, it offers a practical yet theoretically grounded framework for addressing 21st-century infrastructure challenges. This accessible and forward-looking guide is valuable for anyone involved in shaping the future of urban systems, from engineers to urbanists.