This chapter aims to critically evaluate the systematic single-case design on two levels. First, as a tool for obtaining an in-depth and qualitative understanding of the change processes in women experiencing intimate partner violence, who underwent brief psychodynamic psychotherapy within a State institutional context. Second, to examine the challenges this population and working framework pose to the implementation of the time-limited psychotherapy technique. To achieve this, a review of the methodological design is presented, highlighting its relevance within the Practice-Oriented Research paradigm. The chapter further explores the conceptual elements that contextualize the understanding and intervention with vulnerable populations, particularly in cases of intimate partner violence. Finally, the chapter discusses the results of various studies using the single-case design. These studies have focused on understanding change by analyzing significant events in the therapeutic process, as well as observing the particularities and variations in the relational configurations of the clients throughout the intervention. In this regard, it aims to establish a dialogue between research and clinical practice with the goal of contributing to the implementation of intervention frameworks and clinical competencies that are relevant and sensitive to the needs of this vulnerable population.