This paper sheds light on the relatively unexplored question of how interventionist research (IVR) is actually conducted in management accounting and what kind of tensions it involves. The central starting point of the paper is viewing good IVR as producing contributions that are not only practically relevant but also theoretically significant, implying that an interventionist researcher has to be effective in both the emic and etic domains. The paper has two layers: the underlying interventionist case study of one of the authors and the reflective analysis based on that, to which the research question and the paper's purpose relate. The underlying study was a longitudinal IVR project including extremely close collaboration with the case firm. It contributed to the cost accounting literature on component commonality, advancing it to the earlier uncharted engineering-to-order production context. Based on this underlying study, the reflective analysis focuses on the various ways in which a researcher's intervention functions as the central driver of an interventionist study. Specifically, it elaborates on the view that the process around interventions is a ‘battlefield’ of various competing agendas and interests, which an interventionist researcher should balance in order to start, proceed and eventually successfully complete the research project. The balancing acts form a dialogical series of negotiations, relating to both the theoretical and empirical domains. Theoretical contributions of IVR projects tend to emerge in these dynamic processes, in which the researcher feels high pressure to show competence in both domains. However, the battlefield around interventions, though challenging for all parties, is also a rich and inspiring field of opportunities for exchanging knowledge between researchers and practitioners. Hence, IVR projects offer a potential avenue for producing new knowledge, with the two parties collaborating in the spirit of engaged scholarship.