This paper analyses technology-enhanced teaching and learning (TET/TEL) design in the context of in-service teacher training. It is presented as a creative (Glăveanu, 2015, 2020), agentive (Sannino, 2015) activity to help teachers transform teaching and learning and address the challenge of integrating digital technology and education in the classroom (Giraudon et al., 2020). Mainly based on third generation (Engeström, 2001, 2009) of cultural-historical activity theory (CHAT) and in line with epistemological pluralism (Turkle & Papert, 1990), this study also draws upon contributions in didactics and cognitive sciences. It develops the theoretical argument leading to a formative intervention (Engeström, 2011) inspired by the Change Laboratory methodology (Virkkunen & Newnham, 2013). The Change Laboratory is aimed at co-designing TET/TEL scenarios for teachers and thus to model a new concept (Engeström & Sannino, 2010) for teaching and learning. To support this process, teachers are assisted by a card deck as a design artefact. The cards represent the potential components of a TET/TEL scenario.