The increasing platformization of everyday life has recently become a subject of research across the social sciences. This edited volume aims at collecting and strengthening critical research on platform urbanism. Urban scholars have advanced this concept to examine the significance of changing everyday practices and power shifts brought about by the expansion of platform operators into all areas of urban life, such as domestic and rental services, deliveries of meals and groceries, and mobility. Platform urbanism can thus be understood as a special mode of using and producing urban spaces as its inherent mechanisms take on an increasingly central role in refashioning relational dynamics between code, commerce, and corporealities (Barns 2019; Sadowski 2020a; 2020c; Lee et al. 2020).The task of critical platform research lies in engaging with the sociospatial and normative implications of platform-mediated urban life. Platformization reconfigures existing digital socio-spatial orders and exacerbates inequalities in cities (Elwood 2021). Moreover, platforms do not only challenge existing regulatory frameworks (Graham 2020); they also increasingly shape ways of imagining urban futures and experiencing urban space in what may be called platform-mediated practices of placemaking. Hence, the inclusion in or exclusion from the newly created networks of data, value, and work produces new forms of precarity, injustice, and (in)security.However, beyond a mere 'techno-dystopian' stance, critical platform research also needs to emphasize the call to understand platforms as well as contested sites of social creativity and everyday appropriations (Leszczynski 2020;Elwood 2021;Richardson 2020;Pentzien 2021). Rather than yet another critique of Uberization or Airbnbization in cities, this volume comprises critical debates of the actual consequences of digitalization for socio-technical relationships between citizens, cities, and urban infrastructures with reference