Fairness is a recurring challenge in grassroots digital infrastructures, where collective action depends on volunteer contributions. This paper presents a study of Foodsharing.de, a grassroots FOSS platform with 185,000 members rescuing and redistributing surplus food. Drawing on 25 interviews and long-term activist involvement, we analyze two justice-oriented features: the Cherry-Picking Rule (distributional fairness) and Commitment Statistics (contributional fairness). We show how these fairness features become deeply entangled in practice and how they operate as policy-in-code, inscribing fairness logics into software and redistributing not only food and labor but also authority within the community. Rather than settling questions of justice, these interventions trigger renewed negotiation across deliberative spaces and everyday coordination, as encoded rules are interpreted, contested, and adapted. Building on these dynamics, we outline governance directions for justice-oriented grassroots infrastructures, highlighting the need for contestability and accountable autonomy to sustain negotiation and align technical change with community legitimacy.
ACM CHI Conference on Human Factors in Computing Systems