Interweaving systems, embedding practices: Multi-system practice constellations in just sustainability transitions

• Identifies need to study multi-system practice constellations for just sustainability transitions. • Shows how everyday practices interact with transitions across mobility, housing, and food. • Identifies four interaction modes (contesting, adjusting, reconfiguring, and converging) linking systems and practices under vulnerability. • Uses persona-based vignettes to reveal lived climate and health inequalities in transitions. Urgent climate action and sustainability transitions remain insufficient, with escalating climate change impacts on human and environmental health disproportionately affecting vulnerable populations. Dominant frameworks in transition research often sideline the lived experiences and adaptive practices of these non-elite actors. This paper argues for a shift in perspective by introducing multi-system practice constellations as interconnected bundles of everyday practices that occur across provisioning systems, including mobility, housing, and food. Through a synthesis of systems thinking and praxeological approaches, we explore how social practices interact with ecological, technological, and institutional dynamics in co-evolving, uneven ways. Drawing on persona-based vignettes from an exploratory study in Austria, we examine how vulnerable population groups perform practices including cycling, heating, and food shopping, revealing four recurring interaction modes: contesting, adjusting, reconfiguring, and converging. These constellations expose how transitions are already being negotiated in daily life, not as innovations per se, but as precarious improvisations shaped by structural constraints and fragile agency. We conclude that understanding transitions through the lens of multi-system practice constellations offers a more equitable and grounded pathway toward just sustainability transitions that accounts for who is left out, what is taken for granted, and where systemic change is most urgently needed.