The smart city is the idea that computational sensing can narrow the gap between economic development and urban infrastructure’s capacity to accommodate growth. Yet the recent global north-south dissemination of “smart” seems to be exacerbating sociospatial segregation, especially human displacement. These tensions echo those taken up by Participatory Action Research (PAR), advanced by Paulo Freire and Orlando Fals Borda in the 1970s. Drawing upon the case of a community-based data project in São Paulo, Brazil, we present a participatory methodology for translating citizen-sourced data into urban design metrics for informal settlement redevelopment. We argue that understanding Information and Communication Technologies (ICTs) through the lens of PAR ensures that data sensing is tied to meaningful issues, not just sensor deployment. On this basis, we argue that what matters for urban growth is not the “smart” label, but democratic modes of data collection, visualization, and analysis. We conclude by discussing how inclusive Information Technology (IT) environments might guide the future of urban planning and policy for informal settlement redevelopment.