About Langfuse Open Source LLM Engineering Platform that helps teams build useful AI applications via tracing, evaluation, and prompt management ( mission, product ) We have the chance to build the "Datadog" of this category; model capabilities continue to improve but building useful applications is really hard, both in startups and enterprises Largest open source solution in this category: >2k customers, >14M monthly SDK downloads, >6M docker pulls We raised money from world class investors (Y-Combinator, Lightspeed, General Catalyst) and are default alive by making more money than we spend We're a small, engineering-heavy, and experienced team in Berlin and San Francisco ( how we work ) About the Role In short: We're hiring a Frontend Engineer to build performant, scalable user interfaces for our rapidly growing LLM engineering platform. 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. See full stack here. React Frontend and Backend in Typescript (including Express, NextJs, Tailwind, Prisma, tRPC) What we're looking for 3 years of experience in frontend development Experience building highly performant front-ends. 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 Hiring Process We can run this process in less than 7 days. 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 Links Our codebase: GitHub Repository Ben Kuhn on Impact, Agency and Taste Who we are & how we work