Realtime Without a WebSocket Service

Short summary

A technical tutorial showing how to build realtime updates using Postgres LISTEN/NOTIFY paired with server-sent events (SSE) from a serverless function, eliminating the need for a dedicated WebSocket service. The key insight is that each serverless isolate maintains its own LISTEN connection to Postgres, which acts as the shared fan-out point across isolates. The author notes this approach is for small live events, not durable queues, and warns that LISTEN requires an unpooled direct connection.

• •Postgres LISTEN/NOTIFY plus SSE from a serverless function replaces a WebSocket service for realtime updates
• •Each serverless isolate opens its own LISTEN connection; Postgres fans events across all isolates
• •LISTEN needs a direct unpooled connection; this pattern is for small live events, not durable queues

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