Building Capacity for Quality Teaching in Australian Schools, 2018–2023, remains unprecedented in the Australian education research landscape for its investment, scope, and ambition. It was generously supported by a $17.2M philanthropic grant from the Paul Ramsay Foundation as well as cash and/or in-kind support from the NSW Department of Education, the Australian Research Council, and the University of Newcastle. Through three interrelated activities – research, scaling, and setting up a sustainable business model – we set out to comprehensively explore what the ‘Quality Teaching Rounds’ (QTR) approach to teacher professional development could do for schooling in Australia.