How do social media platforms influence democracy? Karoline Helbig explores how the logics and architectures of these platforms structure communication processes. She begins by collecting and systematising central theoretical concepts from the deliberative systems approach, focussing specifically on those pertaining to the structures of and normative standards associated with deliberative systems. Based on these theoretical foundations and drawing on digitisation research, she then situates social media platforms within society-wide deliberative systems. She offers a nuanced analysis of the specific characteristics of digital communication and of how they affect the qualities of deliberation throughout the system. This study speaks to scholars, policymakers and readers concerned with democracy in the digital constellation.