Decentralized Discourse: Interaction Dynamics on Mastodon

Decentralized online social networks, such as Mastodon, present compelling alternatives to centralized platforms such as X (formerly Twitter).Since its inception in 2016, Mastodon has experienced consistent growth, with a notable surge as users transitioned away from X. Its open-source framework and decentralized design have facilitated swift expansion across the Fediverse.In this study, we explore the communication dynamics between Mastodon instances and the distribution of user communities, emphasizing their effects on cross-server communication -a critical scalability issue as the Fediverse continues to expand.We developed and analyzed network models at both the instance and user levels, introducing novel metrics to evaluate how communities align with instance structures.Our findings highlight potential scalability issues stemming from imbalances in instance sizes and misaligned community distributions.