Though they share the word design, the practices of urban design and product design share little in principles and processes. The technologies underlying ‘Smart Cities’ enable a convergence around the ‘Interaction Design’ of connected devices and environments. The focus of Social Practice Theory also points to the importance of these mid-sized mediators for determining the regimes of urban life as lived. How then should we do urban scale interaction design? This is not merely a pragmatic question. What is at issue in the politics of autonomia in the context of collective cities is a choice about scale, mediating between the resistant smallness of subsistence and acceding to global flows of capital. To use an old language, how to interaction design ways of dwelling in cities no longer structured by grand narratives? These practical and theoretical issues will be discussed through a case study of Sharing Economies and the way these initiatives quickly switched from resistant systems for product sharing to appropriate systems of labor cooption.