In short: We are hiring a (senior) Backend Engineer to make our systems and infra keep up with our globally growing user base and billions of monthly events to process. 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: Optimizing the latency of complex database queries in Postgres or Clickhouse Adding Redis queues and a worker container to our stack to execute async tasks Building a POC to try out Clickhouse for our needs Re-building our SDKs to execute networking fully asynchronous Write Terraform code to scale Langfuse containers according to custom metrics Tech Stack You should be familiar with a majority of these but we trust that you can pick up a new language/framework quickly. Frontend and Backend in Typescript (including Express, NextJs, Tailwind, Prisma, tRPC) Clickhouse, Postgres, Redis, S3 Client facing SDKs in Python and Typescript What we're looking for Experience in maintenance of highly reliable and scaling infrastructure 3 years of experience in backend or full-stack development Excited about open source software Experience with the trade offs of handling large amounts of data Hard worker and thrive working in a small and accountable team A CS/quantitative degree is preferred Bonus Experience with or interest in SDK design and DX 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 Project you could have built: Infrastructure Evolution Blog Post Our codebase: GitHub Repository Ben Kuhn on Impact, Agency and Taste Who we are & how we work