Frontend Engineer at Langfuse (W23) €70K - €160K EUR Open source LLM engineering platform Berlin, BE, DE Full-time US citizen/visa only 3+ 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: React, TypeScript Frontend Engineer In short: We're hiring a Frontend Engineer to build performant, scalable user interfaces for our rapidly growing LLM engineering platform. 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 from Berlin, Germany. What you'll do Past projects you would have led: Come up with an improved architecture for our frontend application Build self-serve dashboards to generate insights into billions of LLM executions of our users Creating performant table components with a focus on usability and fast rendering times Implementing advanced filtering and search interfaces for complex datasets Tech Stack You should be familiar with a majority of these but we trust that you can pick up a new language/framework quickly. React Frontend and Backend in Typescript (including Express, NextJs, Shadcn, Prisma, tRPC) What we're looking for 3+ years of experience in frontend development Experience building high-performance web applications that handle large datasets Strong understanding of React, TypeScript, and modern frontend tooling Experience with state management and data fetching patterns Hard worker and thrive working in a small and accountable team Excited about open source software A CS/quantitative degree is preferred Bonus Performance optimization and profiling experience ML/AI experience Impressive achievements from previous careers or side projects Previous startup or founding experience Why Langfuse? You are joining really early Strong Product Market Fit! We are building a very small but highly capable team Only hiring Engineering in foreseeable future Strong customer & revenue growth Building picks and shovels for the hottest AI companies Building for very sophisticated technical users Competitive salary & equity Performance and learning focused culture Everyone on the team says: "best place I've ever worked at" How we work Engineering based in Berlin ( we aim for 4-5 days in the office ) No more than 2 short scheduled meetings per week Extreme ownership & autonomy how and what to work on Links Our codebase: GitHub Repository Ben Kuhn on Impact, Agency and Taste Who we are & how we work 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 Jump on a intro call with our CTO Technical Deep Dive interview Super Day ( half or full day in Berlin Office ) Meet the other founders (short calls) Decision & Offer