The goal of this conceptual paper is to develop enhanced understandings of mathematics teacher design and design capacity when interacting with digital curriculum resources. We argue that digital resources in particular offer incentives and increasing opportunities for mathematics teachers’ design, both individually and in collectives. Indeed they require increased design expertise because of the changing nature of the resources. Drawing on the literature (1) we suggest ten questions providing a tool to study teacher design processes; and (2) we propose three components for exploring teacher design capacity. Building on two main theoretical areas (i.e. teaching as design; documentational approach to didactics) we propose to deepen understan...