Sensors, mobile phones, cars, cameras, and drones are just some of the devices that are almost continuously collecting data in the metropolis. The wealth of data in cities is staggering, making them ideal spheres for data science applications such as machine learning, but also critical focal points for ensuring privacy, security, and fairness in the use of those data. For this effort to be optimal, data generators, analyzers, and users need to coordinate their efforts and aims. The Metropolis Project catalyzes and serves as a connection hub for such interdisciplinary endeavors.