Product Engineer (Growth)
LangfuseBerlin, Germany • London, England, United Kingdom • Germany • Paris, Ile-de-France, France • Zurich, Zurich, Switzerland
Posted February 17, 2026
Full Time
About the Company
Langfuse is an open‑source observability platform that enables teams to develop, monitor, evaluate, and debug large language model (LLM) applications. It offers SDKs for Python and JavaScript, a unified dashboard, and tools for prompt management, automated testing, and human‑in‑the‑loop annotation, allowing developers and product managers to track cost, latency, and user feedback. The platform is self‑hosted in minutes and already trusted by thousands of users, from YC startups to enterprises such as Khan Academy and Twilio, for its reliability and performance. Langfuse’s distinctive value lies in its tight integration with popular LLM frameworks (OpenAI, LangChain, Llama‑Index, Vercel AI SDK) and its community‑driven open‑source ecosystem that fuels rapid iteration and continuous improvement.
Job Description
Product Engineer (Growth) at Langfuse. We're a small, engineering-heavy team in Berlin and San Francisco building the 'Datadog' of open-source LLM engineering platforms. Our product helps teams build useful AI applications via tracing, evaluation, and prompt management. We're looking for a full-stack developer to join our growth engineering team and drive user growth through product lead growth.
Requirements
- Drive to learn fresh things
- A hang for business
- Experience in full-stack development
- SQL skills (for analytics)
- Excited to talk to and think like our users
Benefits
- Comprehensive health insurance
- Flexible work arrangements
- Professional development opportunities
- Generous parental leave
- Flexible vacation policy