As in many areas of society, educational institutions are beginning to adopt all manner of automated decision-making (ADM) technology. This chapter examines one such example – a facial recognition system that promises to automate the registration of students’ in-class attendance. The chapter explores how this seemingly innocuous system foregrounds a range of ways in which initial aspirations of ADM designers and developers can bump up against context-specific practices and understandings. In particular, the chapter explores how the ADM technology is designed around a simplified codification of classroom processes which itself leads to the insertion of new rationalities and ontologies into teachers’ workplaces. With teachers and students tending to be sidelined in this process, the ADM constitutes a subtle ‘de-professionalising’ presence in the working lives of educators. While ADM usually promises to overcome a number of human-related frictions, in the case of the automated ‘roll call’ these frictions are a key element of the relational work that make classrooms continue to function relatively smoothly on a day-to-day basis.