Bluesky is built by around 10 engineers, and has amassed 5 million users since publicly launching in February this year. A deep dive into novel design decisions, moving off AWS, and more.

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Bluesky is a decentralized social network that allows users to own their data and services. It has experienced rapid growth and has implemented unique engineering solutions. The architecture has evolved from a v1 architecture that was not scalable or federated to a v2 architecture that is scalable and federated. Bluesky faced scaling issues with PostgreSQL and migrated to ScyllaDB. The infrastructure was initially hosted on AWS but was later moved to on-prem for cost and performance reasons. Building a social network comes with typical firefighting issues and outages are not life-or-death crises. Bluesky actively responds to user feedback and focuses on real-time support. Decentralized social networks offer advantages such as data ownership and customizability.

Building Bluesky: a Distributed Social Network (Real-World Engineering Challenges)

3. v1 architecture: not really scalable and not federated – yet

4. v2 architecture: scaleable and federated