companies

Langfuse

Open-source LLM engineering platform for tracing, evaluating, and managing prompts across production AI applications.

Langfuse builds an open-source platform that lets engineering teams see what their LLM applications are actually doing in production: every prompt, tool call, retrieval step, and token spent, laid out as a searchable trace. Teams use it to debug why an agent went sideways, run evaluations against real production traffic, and manage prompt versions without redeploying code. Founded in Berlin in 2022 by Max Deichmann, Marc Klingen, and Clemens Rawert, the company grew out of frustration with black-box LLM debugging during earlier agency work, went through Y Combinator's Winter 2023 batch, and built a following among developers who wanted an MIT-licensed alternative to closed observability tools that could be fully self-hosted rather than paywalled feature by feature. In January 2026, Langfuse was acquired by ClickHouse, the open-source analytics database company that already powers much of Langfuse's own backend. The product keeps its open-source license and self-hosting path under the new ownership, with the founding team continuing to lead it from Berlin and San Francisco.

Founded

2022

Headquarters

Berlin, Germany

Sector

infrastructure