In response to the escalating impact of mindless consumption in the fashion and IT industry, we began to think of and with a constraintbased approach to interaction design. This paper describes a research through design investigation into a paradigm of constraintbased design, founded on the practical and perceived constraints of solar-powered internet. Our intention is not to examine individual consumer as a site for sustainable transition, but the industries and industry practitioners at the interface with consumers. We employed strategies that included optimisation as a form of minimisation, visibility as a means to mark existing absence, offloading from automation, and the design of dead-ends. We discuss the challenges in learning to design against the cornucopian paradigm. While the overall vision of an internet powered by the sun seems at once desirable and achievable, the pursuit of a constraints-based interaction design highlights the desire to confirm the dominant paradigm of abundance.

The multiple unfolding crises that threaten life on Earth keep many of us awake at night and leave us at a loss about how to meaningfully respond. Much of humanity's efforts to address the crises are ultimately aimed at upholding the current unsustainable paradigm of infinite growth and exploitation of both natural resources and humans. In this paper, we offer the Two Loops model of change as a framework for understanding the interrelated crises of our times - the meta-crisis - to help us find clues for personal agency and also hope. Notably, Two Loops asks us to face the need for hospicing and grieving what is dying, reorienting computing to work to what comes after and what must be protected and saved. We work through the model's various spaces for agency, i.e. innovating, naming, connecting, nurturing, illuminating in the emergent System; and stewarding, hospicing, composting and transitioning in the dying dominant System. We suggest examples and clues as to where computing and HCI professionals' agency might lie in and between the two Systems in terms of skills, tools, practices and projects. Moving forward, we welcome a deeper, large-scale collaborative mapping of the possible contributions of our profession, to include all the different specialisms of our field in the picture of how we can be of service to liveable futures.

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.