Senior Product Engineer
š Germany
š Spain
š France
š United Kingdom
š Netherlands
š Zurich, Switzerland
š Munich, Germany
š Berlin, Germany
š Paris, France
š London, United Kingdom
Used Tools & Technologies
Machine LearningRequired Skills & Competences
Tag name is followed by "@" symbol and proficiency level value.
About proficiency levels:
- 1-2 ā basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;
- 3-6 ā daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;
- 7-9 ā you are an expert, you can teach others, you know all the pitfalls and tricks;
- 10 ā exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.
Redis @ 4
Terraform @ 4
TypeScript @ 4
Python @ 4
Hiring @ 4
PostgreSQL @ 4
Next.js @ 4
React @ 4
API @ 4
Experimentation @ 4
LLM @ 4
AI @ 4
ClickHouse @ 4
- 1-2 ā basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;
- 3-6 ā daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;
- 7-9 ā you are an expert, you can teach others, you know all the pitfalls and tricks;
- 10 ā exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.
Details
About Langfuse
Open Source LLM engineering platform that helps teams build useful AI applications via tracing, evaluation, and prompt management. Langfuse is now part of ClickHouse. The company is engineering-heavy with teams in Berlin and San Francisco, hiring for engineering in EU timezones, and expects one week per month in the Berlin office.
Why Product Engineering at Langfuse
Your work will have an outsized impact. Everything you build is open source (MIT) and immediately visible. Langfuse has a large community and many SDK downloads. Product engineers deliver new features end-to-end: understanding user problems, deciding what to build, and shipping solutions.
You will grow at Langfuse by
- Owning features end-to-end: talking to users, writing specs, shipping code and docs, and publishing changelog posts under your name.
- Working across the full stack: React frontend, Next.js backend, ClickHouse analytics, Python and TypeScript SDKs, public docs, Terraform modules, and more.
- Talking to users constantly: calls, community channels, and support requests.
- Writing public documentation for features you own.
- Shipping publicly during Launch Weeks (regular feature release cadence).
What we're looking for
- Someone who has built features or entire products from scratch end-to-end.
- Experience building and shipping user-facing products end-to-end, ideally in TypeScript/React and with exposure to data-intensive backends.
- Ability to manage projects independently and develop conviction about what to build and how to ship it.
- Taste for great developer experience: API design, UI details, and clear documentation.
- Interest in open source software and excitement about talking to developers about their problems.
- Thrives in a small, accountable team where output is visible and matters.
- CS or quantitative degree preferred.
Bonus points:
- Experience with ClickHouse, analytics databases, or building complex data visualizations.
- Former founder or early startup experience.
- Contributions to popular open source projects.
- ML/AI background or familiarity with the LLM framework ecosystem.
Process
The hiring process can run from application to offer in less than 7 days.
Tech Stack
Langfuse runs a TypeScript monorepo: Next.js on the frontend, Express workers for background jobs, PostgreSQL for transactional data, ClickHouse for tracing at scale, S3 for file storage, and Redis for queues and caching. The team expects familiarity with a good portion of this stack and trusts engineers to pick up the rest quickly.
How we ship
- Engineers take ownership: identify what to build, propose RFCs, and ship them.
- Collaborative culture: whiteboard sessions and frequent mentorship through code reviews.
- Maker schedule with two recurring meetings a week (short Monday check-in and Friday demo).
- The team uses AI extensively in workflows and encourages experimentation with new tooling and AI workflows.
Why Langfuse (now part of ClickHouse)
- Work at the forefront of AI and LLM engineering, building devtools and developer-facing products where reliability and performance matter.
- Contributions are public and visible; you will ship under your name and present work during launch events.
- Solve hard engineering problems around SDKs, tracing, rendering large prompts in the UI, and processing terabytes of data per day.
- Close collaboration with ClickHouse and opportunity to learn from their infrastructure expertise during a period of strong growth.