The current Quality Initial Teacher Education Review acknowledges the positive contribution of TPAs to the classroom readiness of graduates, yet the review’s Expert Panel has questioned the benefits and costs of the number of TPAs in operation. In this presentation we draw on outcomes from our research into the development of a summative high-stakes mandatory capstone assessment, the AfGT, and what this meant for the initial teacher educators who co-designed the instrument. The AfGT co-designers were a community of practice of six teacher education academics from three ITE institutions in two different states in Australia. Using collaborative self-study as a methodology we examined our reflexive narratives and social processes contributing to the development of the nationally mandated TPA. Data were generated in a systematic and structured manner over a sustained period of time through reflective writing and dialogue. The data were interrogated individually and collaboratively and three emergent categories were identified: leadership and social practice, dispositions and context, and tensions. The focus of this presentation is not on the endorsed AfGT instrument itself, but on the social processes that occurred when designing and developing the AfGT. In our research we found that collaborative leadership and key personal dispositions are at the heart of the design process, and that these dispositions contributed to the ways in which we navigated the tensions that arose during this collaboration. Teamwork in this design process was embraced with respect, trust and openness in an environment that supported the exercising of scepticism and critical thinking and the sharing of expertise. . There was a development and strengthening of relationships with colleagues in different parts of Australia who worked in institutions with different histories, programs and delivery models. The diversity of each other and of our institutions was recognised, respected and harnessed.The ITE reforms since the Teacher Education Ministerial Advisory Group (TEMAG) review have created shared challenges for the sector but have provided new opportunities for individuals who work in these institutions. While the outcomes from our study are not generalisable to other contexts, we consider that the learning that we gained as a consequence of engaging in this collaborative and participatory work is one way to consider the social benefits and costs of developing a TPA across multiple institutions.