Langfuse uses ClickHouse Cloud to power real-time observability and analytics for complex, agentic LLM applications at scale. Migrating from Postgres to ClickHouse Cloud cut query latency from minutes to near real-time while supporting rapidly growing ingestion volumes. An upcoming shift to immutable, wide-table modeling reduces memory usage by 3x and results in 20x faster analytical queries. Summary When Langfuse first shared its journey from Postgres to ClickHouse in March 2025, the challenge.