There have been repeated calls for more ecological approaches to Sustainable HCI, and for the inclusion of the sociopolitical, structural, historical, and geographical aspects that shape technology-mediated practices of sustainability. Contributing to this discourse, and drawing from scholarship on Law and IT, this paper explores how the law, technology design, market mechanisms, and social norms enable and constrain behaviours — that is, how they regulate them. We use these modalities to discuss two digital technologies: a gig-work platform mediating practices of waste transportation, and an eco-visualisation platform scraping sustainability reports of publicly listed companies. The analysis expands on the set of dynamics that characterise the relations between these practices of sustainability, technology design, and regulation. We conclude by discussing the relevance of this conceptualisation for HCI, specifically in defining the roles of designers as regulators, and regarding design for sustainability as constituted through varying entanglements of these modalities.

When designing with and for complex sustainability processes like waste management, it is crucial to understand digital technologies as entangled with broader systemic factors, including physical infrastructures and regulatory instruments. Within the case of organic household waste management, this pictorial aims at making such relations visible through design methods. We have used yarn to represent the different threads of these entanglements and defined specific configurations: tangles, knots, loose ends, and frayed threads. We discuss how the design practice of giving form to these entanglements can make complex relations between digital technology, infrastructures, and regulatory instruments more visible and actionable for HCI, and explore how digital technologies are – and can be – made to work within them.