What does it mean to be radical architect or designer today? Never before have cities mattered as much to the future of humanity. As David Harvey attests, we have sleepwalked unknowingly into a full-blown “crisis of planetary urbanization”, with acute social, political, and ecological dimensions. Cities are fundamentally places of opportunity – after all, urban migrants continue to be drawn in their millions by the promise of security as well as upward mobility. But cities are too often sites of yawning inequality, where land, housing, infrastructure, and services are transformed into symptoms of exclusionary growth. Faced with contemporary urbanization patterns, we are forced to question how cities and city-making have traditionally operated. More to the point, as architects and designers we are forced to rethink how we can operate within the city, learning from its emerging intelligence and shaping its outcomes to radical and tactical ends.