James Calleja, PhD, is a senior lecturer on the professional learning and development of educators for the Faculty of Education at the University of Malta where he coordinates the master’s in educational leadership and management course. James also works closely with teachers and schools to support them in developing their continuing professional development (CPD) programmes. He leads the Collaborative Lesson Study Malta (CLeStuM) programme (www.clestum.eu) and is a council member of the World Association of Lesson Studies (WALSs). James is also a fellow of the International Society for Design and Development in Education (ISDDE) and the Centre for Mentoring, Coaching, and Professional Learning (CollectivED). Before joining the University of Malta, he taught mathematics for 23 years, including 6 years as a Head of the Department. His main research interests are CPD, mathematics education, teacher learning, task design, inquiry-based learning, and lesson study. He has presented his research in a number of conferences both locally and internationally and has also published his research in local and international peer-reviewed journals.