Ubiquitous computing and the internet of things are often referred to as prime examples not only of new modes of computing, but of a new paradigm of mediation itself. If Lewis Mumford could already ascribe key characteristics of media – such as storage and transmission – to the city, so that the city could in itself be understood as a medium (see Kittler, 1996), then nonetheless something changes considerably once ‘the city itself is turning into a constellation of computers’, as Michael Batty noted around twenty years ago (1997: 155). Today the city is indeed awash with distributed and networked computation, and many forms of knowledge and practice not only in architecture and urban planning turn the city into a subject of computational practices while equipping it with computational capacities. Software codes city space and thereby allows for the co-production of its spatiality; more and more space in the city is reliant on code, producing ‘code/space’ wherein a space would simply not function without software (Kitchin and Dodge, 2011). This themed issue on ‘computing the city’, which emerges from a workshop with the same title held at the Centre for Digital Cultures at Leuphana University Lüneburg in 2014, focuses specifically on the development of urban ubiquitous computing, its status as media infrastructure, its complicity with logistics, as well as its contingent histories and virtual futures. The approach to computing in the city taken here questions the accustomed self-descriptions of a mediated society as completely new infrastructures of living and dwelling. This is not yet another themed issue on the ‘smart city’ – as we will see below, a consideration of computing in the city far exceeds the ways in which the smart city as discourse and project seeks to capture our imaginaries of future technological cities.