The chapter is structured in two main sections. The first one looks at the role that data plays in the production of smartness. The city is envisioned as a physical incarnation of an immense cloud of Big Data; its purpose and value are generated by speculation on how sensitive its infrastructure of sensors and cellular communication towers are. On how much data the city can generate and on how capable its high-bandwidth conduits are to circulate these data.The second section of the chapter unfolds the properties of test-bed urbanism, the name we have given to the distinguishing modes of operation we saw at stake. The test bed thus transforms time, change and events into uncertainties and trials. This is a new form of administration that lacks norms, frequency distributions and the statistical apparatus of older demographic, state and economic thinking in the name of a new epistemology of infinity.