Customer Engineer

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. TL;DR Langfuse is looking for a hands-on Customer Engineer who will own the front line of our customer experience, keep a tight feedback loop with product engineering, and help thousands (metrics) of AI‑product teams succeed with tracing & evals. You’ll split your time roughly 60 % on helping our broad user base / 40 % key‑account enablement, use a modern AI‑enhanced support stack (Plain.com, Dosu, Inkeep, in-house tooling), be one of the core public faces of langfuse across GitHub and content, and work in‑office in Berlin‑Mitte, shipping improvements to documentation and product every single day. About Langfuse Langfuse is building the open-source LLM engineering platform. We help engineers understand how users interact with their LLM applications and how they can improve them. Have a look at our website, our GitHub and especially our technical docs to learn more. We have raised a $4m seed round from Y Combinator, Lightspeed and General Catalyst. Thousands of engineers use Langfuse to observe, debug and improve their LLM apps. Our culture is “no‑rules‑rules,” high ownership, and obsessive customer focus. Support is not a cost‑center but a product discovery engine: engineers own their features end-to-end, fixes land fast, and users ideally see “magic” when their feedback ships the same day. What you will be working on 1 —Obsessing over our Users (≈ 60 %) Triage & solve inbound questions from Plain’s unified inbox (Slack Connect, email, GitHub, Discord). Author doc PRs, snippets and auto‑reply prompts so the next 1 000 teams self‑serve the answer. Escalate bugs to product engineering and close the loop with the customer once shipped. Ship small improvements yourself to close the loop even faster. Triage & solve inbound questions from Plain’s unified inbox (Slack Connect, email, GitHub, Discord). Author doc PRs, snippets and auto‑reply prompts so the next 1 000 teams self‑serve the answer. Escalate bugs to product engineering and close the loop with the customer once shipped. Ship small improvements yourself to close the loop even faster. 2 —Delivering Excellence to our Key Accounts (≈ 40 %) Act as named technical contact for a handful of high‑volume or enterprise teams; jump on Slack huddles, unblock integrations, surface best practices. Track their feature requests, quantify impact, and champion them on our roadmap. Act as named technical contact for a handful of high‑volume or enterprise teams; jump on Slack huddles, unblock integrations, surface best practices. Track their feature requests, quantify impact, and champion them on our roadmap. 3 —Improving our Product Maintain the support → issue tracker flow: label, cluster, and prioritise insights so Product Engineering can act fast. Spin up proof‑of‑concepts (TypeScript/Python) to reproduce edge cases or demonstrate work‑arounds. Maintain the support → issue tracker flow: label, cluster, and prioritise insights so Product Engineering can act fast. Spin up proof‑of‑concepts (TypeScript/Python) to reproduce edge cases or demonstrate work‑arounds. 4 — Bonus Points (Developer Advocacy) Publish blog posts, sample repos, or videos on as the go to in-house product expert in Langfuse. The Opportunity Immediate impact: your answers unblock thousands of developers every month. Directly work with our OSS community & develop a public profile. AI‑powered workflow: we heavily use LLMs in support—auto‑draft replies, ticket routing, summarisation—see our blog post for details. Product influence: work with product engineering: many of today’s flagship features started as “support requests.” Immediate impact: your answers unblock thousands of developers every month. Directly work with our OSS community & develop a public profile. AI‑powered workflow: we heavily use LLMs in support—auto‑draft replies, ticket routing, summarisation—see our blog post for details. Product influence: work with product engineering: many of today’s flagship features started as “support requests.” Who we are looking for Solid foundations in software (CS degree or comparable projects). New grads and career‑switchers encouraged. You enjoy talking to other engineers, debugging APIs, and turning chaos into crisp docs. Strong writing: short Slack messages and long‑form guides. Curiosity for LLM application development Bonus: past B2B support, open‑source maintainer, or DevRel history. Solid foundations in software (CS degree or comparable projects). New grads and career‑switchers encouraged. You enjoy talking to other engineers, debugging APIs, and turning chaos into crisp docs. Strong writing: short Slack messages and long‑form guides. Curiosity for LLM application development Bonus: past B2B support, open‑source maintainer, or DevRel history. Team, Values & Benefits You’ll join a 10‑person team in our Berlin‑Mitte office, 4-5 days/week in-office + optional SF trips high‑quality gear, team offsites, zero‑bureaucracy budget for learning, and equity in a fast‑growing company. 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 Intro call (30 min) – meet a founder, talk motivation & logistics Functional deep‑dive (45 min) – talk about your experience that maps to this role, what makes you excellent and the perfect fit Coding exercise (90 min) – this role is technical, during this call we will go deep on your aptitude to help customers get technical issues resolved and small fixes shipped On‑site Super‑Day (½ day) – we simulate a couple of core activities of this role during a mini-work-trial to make both sides go from “Yes” to “Hell Yes”, during this day you will also get to meet the whole team Decision & Offer – usually within 24 h. We are very public about our strategy and product thinking, so feel free to start some deep research threads on this. Throughout the process, there will be ample time for any questions you may have that haven't already been addressed. We are generally super transparent, don't hesitate to ask any of the interviewers.