This chapter compares how experienced and early career teachers design for learning. The chapter draws on narrative accounts, design outcomes and video analysis from simulated design work by Australian primary school teachers to show differences in the sequence of design activities and the influences on design decisions based on the level of professional experience. This analysis draws on the classic expert-novice distinction which has been used to explore and explain how expertise develops over time across a range of different domains and activities as diverse as chess playing and aviation. We naturally expect there to be a trajectory for the development of teachers with growing experience, but more years of teaching may not necessarily result in greater design expertise. In fact, the analysis shows that developing design expertise involves not just accumulating years of experience but building sophisticated ways of thinking about and monitoring design work. We build from this analysis to discuss the ways in which professional learning and reflective practices could best support the development of greater design expertise for teachers as they progress through their careers. These findings are relevant not only for individual teachers seeking to undertake self-directed professional development, but also for school leaders and systems engaging in systemic capacity building.