AcquisitionClickHouse · Jan 15, 2026

ClickHouse acquires Langfuse

ClickHouse acquires the open-source LLM observability platform Langfuse as part of its $400M Series D at a $15B valuation — the first big consolidation in agent observability. The open-source core remains maintained; the deal signals that agent tracing is becoming a database-scale problem.

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#langfuse #observability #evals #acquisition

Arena.ai's HarnessTax study tests 21 model–harness combinations across Claude Code, Codex CLI and Pi, finding harness choice can significantly change cost even at similar task success rates. Weeks earlier, SWE-bench Pro analysis showed swapping harnesses moved pass@1 more than model upgrades (23%→52% on GLM-5.2) — and that harness rankings barely transfer across models.

ClickHouse acquires Langfuse

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