The rhythm of change in working life has accelerated, due in large part to the co-evolution of technology and work practices. In these circumstances, theories of learning have started to emphasise creative thinking, collaboration and boundary crossing and to define learning through an emergent process of knowing. Knowing precedes knowledge, both logically and chronologically, since ‘knowledge’ has been proposed as an institutionalised version of ‘knowing’ (Nicolini, Gheraldi & Yanow, 2003). Knowing comes into being through various forms of participation and is formed through negotiations between multiple individuals and interdisciplinary groups. Assemblies of collective units are becoming learners in and for interagency; they are engaged in a process within which ‘agency is forming itself; it is forming while being formed at the same time’ (Stacey, 2001, p. 62). In this chapter, we use the theory of expansive learning as a frame of reference to consider these new forms of learning (Engeström, 1987; 2011). The theory was initially formulated over two decades ago. The theory has been extended and used widely to understand work-based and professional learning and has served as a theoretical and methodical foundation for a variety of studies examining change in various human activities.