How Supabase Rebuilt Postgres for Real-Time Apps

Episode notes

In this episode, Lucas and Luna explore how Supabase, an open-source Firebase alternative, built a real-time layer on top of PostgreSQL that handles millions of concurrent WebSocket connections. They break down the architecture behind Supabase's Realtime server, which uses PostgreSQL's logical replication and Elixir's BEAM VM to stream database changes to client applications with sub-second latency. Lucas explains why the team chose to fork PostgreSQL's replication slot mechanism and how they handle backpressure when clients fall behind. Luna questions the trade-offs of using WebSockets versus server-sent events for real-time data synchronization. The conversation also touches on Supabase's decision to build on AWS's Graviton processors to reduce costs and how the company scaled from zero to over 200,000 users without a dedicated infrastructure team. If you're building a real-time application or just curious about modern database architecture, this episode offers concrete insights into one of the most exciting open-source projects in the cloud space.

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