Digital platforms are increasingly becoming the infrastructure for accessing urban services and spaces under platformised cities. However, how this infrastructure is built spatially, and for whom, remains underexplored in planning research. Drawing on platform urbanism (Barns 2020), code/space (Kitchin & Dodge 2011) and Lefebvre's theory of the production of space, this study theorises that platformised space are politically and economically produced rather than simply technologically given. Taking Zhengzhou, China as an empirical case, the research develops three arguments. Firstly, the embedding of platforms into urban space is shaped by both market and state strategy. As the roles of platforms and the state are spatially selective, it produces a stratified digital space. Besides, platforms have reshaped urban spatial form. Some physical spaces have shrunk, while platform-related spaces have expanded, ultimately reorganizing how urban space operates. These spatial changes are rooted in the spatial arrangement by the three forces: the state, capital, and platform companies. In addition, platforms have become a new spatial form and urban infrastructure. For digital planning, this reframes platform infrastructure as representations of space, foregrounding spatial justice and unequal digital accessibility. This research argues that platform urbanisation reshapes urban space by three parties, namely state policy, capital operations and digital platform companies, through representation, production, and infrastructural embedding. This analysis contributes an analytical framework for digital planning that moves beyond technology-neutral narratives and foregrounds the power relations and inequalities.