Product Engineer at Langfuse (W23) €70K - €160K EUR Open source LLM engineering platform Berlin, BE, DE Full-time US citizenship/visa not required 1+ years About Langfuse Langfuse is building open-source observability and product analytics for LLM applications. We help engineers and companies understand how customers use their LLM applications and how they can improve on them. Have a look at our website and especially technical docs to learn more. About the role Skills: Python, TypeScript In Short: We're looking for an experienced product engineer to ship category defining LLM engineering products. About Langfuse We are building the fastest growing open-source LLM engineering platform. We help engineers and enterprises build and run LLM applications at scale. We've raised $4m from Y Combinator, Lightspeed and General Catalyst. Thousands of teams and engineers use Langfuse daily. Thousands are joining every month. We're a small, focused team working in-person from Berlin, Germany. What you'll do Do whatever it takes to build new features for our users. For this you are not afraid to touch FE, BE, SDKs or Docs You love to communicate with users on a call or in one of our hundreds of slack channels You will come up with a plan on how to build the next big feature at Langfuse and execute on it Doing support Writing docs Tech Stack Frontend and Backend in Typescript (including Express, NextJs, Tailwind, Prisma, tRPC) Clickhouse, Postgres, Redis, S3 Client facing SDKs in Python and Typescript You should be familiar with a majority of these but we trust that you can pick up a new language/framework quickly. What we're looking for Someone who is able to PM and project manage themselves Experience building highly reliable, scaling infrastructure Interest in open source software and talking to users Hard worker who thrives in a small, accountable team CS or quantitative degree preferred Impressive achievements (professional or otherwise) Bonus points: Former founder Experience in SDK design DX, ML/AI background Why Langfuse? Building for very sophisticated technical users Competitive salary & equity compensation Strong customer & revenue growth You are still joining really early Strong in person engineering culture (Berlin-Mitte) Extreme autonomy Performance and learning focused culture Everyone on the team says: "best place I've ever worked at" 2 short scheduled meetings per week Links Our codebase: GitHub Repository Ben Kuhn on Impact, Agency and Taste Who we are & how we work What is a Product Engineer (PostHog) Technology https://github.com/langfuse/langfuse/ Stack: Frontend and Backend in Typescript (T3 Stack including NextJs, Tailwind, Prisma, tRPC), Postgres, Client facing SDKs in Python and Typescript Interview Process Fill out application & We screen your application Call: Intro & CV deep dive with CTO (45min) Call 2: Technical Deep Dive (90min) Onsite Super Day ( half or full day in Berlin Office ) Meet the other founders (short calls) Decision & Offer We expect you to have used Langfuse (you can sign up for a free account here) and skimmed through our documentation and public content.