In this paper, we examine the digital mediation of planning through an in-depth case study of a multi-scale planning development and control data ecosystem that is used to manage and assess the pipeline of planning applications, appeals, building control, and the production of planning statistics and open data. The principal contributions of our analysis are three-fold. First, we highlight how planning work is rarely mediated by a single digital technology, but rather employs a constellation of software and data systems. Second, we chart in detail a planning data ecosystem and its constituent parts, and identify a number of technical, regulatory and socio-cultural data frictions that limit and hinder how a data ecosystem functions. Third, we make the case that individual data systems and data ecosystems may aspire to be perfect but are typically ‘good enough’ in nature. That is, they are functional and perform necessary tasks, but not always in an optimal manner. We contend that ‘good enough’ is a sufficient and reasonable workable solution given contextual factors and the technical, institutional and regulatory challenges of creating and maintaining a complex data ecosystem.