Unfettered growth of slums is a daunting transition challenge and many upgrading programs fail to sustainably improve the livelihoods of slum residents. This paper elaborates a transitions perspective on structural tensions that may lead to success or failure of slum upgrading programs. We conceptualize slums as urban subsystems, governed by sociotechnical (infrastructure) and socioeconomic livelihood regimes (related to production and social reproduction). The framework permits examination of the tensions due to mis/alignments of rules associated with newly introduced infrastructures, and those that regulate existing production and social reproduction practices of slum residents. This approach extends transition studies by accounting for the multi-system interactions between different infrastructure regimes (e.g., transportation, sanitation) and livelihoods within a local sociotechnical system. We apply this framework to an in-depth analysis of a slum upgrading project in Naivasha, Kenya, which was part of a national urban upgrading program covering a total of 80 slums.