This research examines the consequences of a mandatory assessment for pre-service teachers in Australia that is completed during their final teaching placement. The Teaching Performance Assessment (TPA) is an analysis of practice that incorporates video of teaching episodes, observation feedback, and analysis of pupils' work samples. Semi-structured focus groups and surveys were conducted with pre-service teachers and teacher educators to investigate how the assessment item contributes to developing professional understanding and professional practice. Data were analysed using inductive coding that was thematically categorised. The study established that the process of completing the TPA contributed to expanding pre-service teachers' understanding and comprehension of the ways their teaching can improve pupil learning. These results lead to several insights about how a high-stakes assessment task such as the Teacher Performance Assessment can promote the educational growth of pre-service teachers but also brings risks of redirecting the purpose of the placement from its ambition to focus on compliance tactics.