This case study examines the deliberative and participatory processes used by Slum Dwellers International (SDI), focusing on two affiliated federations in Kenya and Malawi. It describes the ways in which participatory mechanisms have allowed SDI federations to self-organise and engage with policymakers at local, national and global level to respond to challenges, including COVID-19. It also reflects on the use of digital tools to strengthen community mobilisation, community data generation and learning processes.