Daniel T. O’Brien is Associate Professor in the School of Public Policy and Urban Affairs and the School of Criminology and Criminal Justice at Northeastern University. His primary expertise is in the use of modern digital data sets to better understand urban processes, particularly the social and behavioral dynamics of neighborhoods. He is co-Director of the Boston Area Research Initiative (BARI), in which capacity he has worked extensively to build effective models of research-policy collaboration that help us to better understand and serve cities. His book The Urban Commons (2018; Harvard University Press) captures the intersection of his scholarly and institutional efforts, using the study of custodianship for neighborhood spaces and infrastructure through Boston’s 311 system to illustrate the potential of cross-sector collaborations in urban informatics.