How to kickstart social innovation processes at the intersection of government, civil society, and the private sector? The #wirvsvirus hackathon, hosted by the German Federal government, mobilized about 26,500 participants generating 1,494 project ideas for resolving the Covid-19 crisis, and 130 teams joined a post-hackathon program supporting scaling up their ideas. By studying the hackathon and the dynamic interaction among organizers, participating initiatives and actors from the public and private sector, the project contributes to research and practice by understanding whether and how this form of participatory organizing of social innovation can serve as a blueprint for tackling other grand challenges. (Source: see link)