ABSTRACT Higher education curricula require regular renewal. Varied expertise is needed to meet the multi-faceted challenges of curriculum development, hence the importance of collaborative approaches. Co-design is one approach to curriculum making as a relational practice, with evidence showing it can improve pedagogical quality and stakeholder involvement via a collaborative ethos that breaks through constraints of individual imagination and assumptions. The actual doing of co-design in higher education remains largely undocumented, limiting our understanding of this crucial feature of contemporary pedagogical innovation and development. This paper combines the theory of practice architectures with practitioner inquiry to explore three co-design projects within a large curriculum transformation initiative at an Australian university. Each involved a course coordinator, educational developer and learning designer working with tutors, students, industry representatives and media producers. Analysis focuses on how co-design team members connected their own actions to those of others, and how they collectively accomplished things that could not have been achieved alone. Identifying these highlights co-design as a process of learning, coming to practise differently, shaped by the site at which it unfolds, but also reshaping this wider context. This analysis sheds new conceptual light on the black box of co-design as enacted in higher education.