Sidewalk Labs offered a unique vision of a new kind of mixed-use, complete community on Toronto’s Eastern Waterfront at Quayside, which they called their ‘city as a platform.’ Key to this vision was a digital layer of highly complex digital infrastructure and systems that enabled the creation and management of digitally-enabled services. Their plan to build a digital layer would enable connectivity, access and data integration across the components of the city’s physical layer. This cross-component integration suggests the potential for deep data interlinking between components of the digital layer with the city’s physical layer. Sidewalk Labs’ ‘city as a platform’ highlighted the potential high levels of complexity in the way interlinked systems and data flows interact within the digital layer, the potential unexpected outcomes in the physical layer and the diverse concerns about digital governance. Therefore, as this case study examined, planning for this transformation requires a holistic evaluation of the digital layer, the digitally-enabled services and its impact on the political, social, economic, institutional, and environmental dimensions.