This interview with Annalisa Sannino and Yrjö Engeström was held on the subject of fourth-generation activity theory. The interview was conducted by Katsuhiro Yamazumi on August 30, 2018, at the Center for Research on Activity, Development and Learning (CRADLE), University of Helsinki, Finland. In order to overcome the limits of the previous three generations of activity theory, an emergent fourth generation of activity theory has to capture new forms of activity, in which the fixed boundaries, constraints, and structures of activity systems are blurred and a significant number of activities are loosely synchronized, interconnected, and combined. The fourth generation of activity theory should expand the unit of analysis to overcome the inner contradictions of the previous three generations of activity theory. Additionally, this new generation of activity theory should attempt to develop collaborative efforts to tackle the ongoing global humanitarian and environmental crises and advance formative interventions during such crises.