Online interactions are often understood through the corporate social media (CSM) model where social interactions are determined through layers of abstraction and centralization that eliminate users from decision-making processes. This study demonstrates how alternative social media (ASM)—namely Mastodon—restructure the relationship between the technical structure of social media and the social interactions that follow, offering a particular type of sociality distinct from CSM. Drawing from a variety of qualitative data, this analysis finds that (1) the decentralized structure of Mastodon enables community autonomy, (2) Mastodon’s open-source protocol allows the internal and technical development of the site to become a social enterprise in and of itself, and (3) Mastodon’s horizontal structure shifts the site’s scaling focus from sheer number of users to quality engagement and niche communities. To this end, Mastodon helps us rethink “the social” in social media in terms of topology, abstraction, and scale.