Since its introduction by Jean Lave and Etienne Wenger in Situated Learning: Legitimate Peripheral Participation in 1991, the concept of communities of practice has been widely adopted by researchers and practitioners in different fields. This has been accompanied by continuous expansion and development of the theory behind the concept. In this interview, Professor Etienne Wenger-Trayner discusses the evolution of the theory of communities of practice in his own work over the past two decades. He talks about the origins of communities of practice as a theoretical approach, identifies three phases through which this theory has evolved, and reflects on his professional trajectory as a theorist and consultant. Using his career as an example, Wenger-Trayner elaborates on the notion of knowledgeability as a relationship individuals establish with respect to a landscape of practice that makes them recognizable as legitimate actors in complex social systems.