Design Engineer

TLDR;

Langfuse is building open source dev tooling for LLM apps based on observability/tracing. We have significant traction and are growing fast. We are looking for a designer / design engineer to help us elevate our user’s experience. We work on-site from Berlin, Germany.

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. We are now looking for a design engineer to join our team in-person in Berlin, Germany.

What You Will Be Working On

Your main responsibility will be to ensure that the Langfuse platform scales. At the core of Langfuse lies the ingestion of millions of events a day via our SDKs. Once the data is in our database, we visualize it in our UI and run async workflows on top of it in the background.

You will be working closely with Marc (CEO) and Marlies

Projects we have worked on in the past that you would have been involved in:

• Optimizing the latency of (analytical) database queries
• Migrating our SDK ingestion API from single event to batched event
• Helping our customers deploy Langfuse in self-hosted, e.g. by updating our k8s helm chart
• Adding Redis queues and a worker container to our stack to execute async tasks
• Building a POC to try out Clickhouse for our needs
• Choosing ORMs for maximum developer productivity
• Re-building our SDKs to execute networking fully asynchronous
  
  

Stack: Frontend Typescript (NextJs, Tailwind, shadcn, Magic UI), Clickhouse, Postgres) — you should be familiar with a majority of these but we trust that you can pick up any new frameworks quickly. Please have a look at our repo to see our architectural choices.

The opportunity

Join a pure-play open source devtool company in Berlin, Germany.

You are joining early. We will treat you as a core member of the team from day 1 and you will be incentivized as such. Your decisions lie at the foundation of how we design our product. Choosing simplet yet appropriate design and anticipating upcoming challenges is key.

You will contribute to a thriving commercial open source project and build in public. You will own much of the public-facing Langfuse user experience end-to-end. `

Who We Are Looking For?

This is the perfect role for an experienced frontend engineer or a designer with good frontend skills who wants to join an early stage company and build it into the leading open source devtools in Europe.

• You are a hard worker and thrive working in a small and accountable team
• You want to take ownership in building out the infrastructure of a fast growing devtool
• You are excited about open source software. You want to talk to our users to understand why they use us and what they require.
• You have 3+ years of experience in backend or full-stack development and know the trade offs of handling large amounts of data
• You have impressive achievements from previous careers and from side projects — we’re excited to hear about these
  
  

Bonus Points

• You’ve started a company before or worked at a very early stage startup
  
  

Team, Values & Benefits

You will join our early core team and work closely with the three founders of Langfuse: Max (CTO), Marc (CEO) and Clemens (COO) and our team (Marlies, Hassieb, Steffen and Jannik).

We work in-person from our lovely office in the heart of Berlin-Mitte. You must be willing to be located in Berlin. We aim for 4-5 days in the office a week.

Our team culture is built around performance and learning. We want to build a small team of highly motivated, independent and intelligent people. We will support and challenge you while granting you autonomy.

A few tidbits that might help you understand what kind of company we are:

• We plan on only hiring engineers for the foreseeable future
• You can expect to have ~1 meeting a day on average
• Reed Hastings’ ‘No Rules Rules’ inspires our culture, here’s a summary
• We’re big fans of Y Combinator and follow its ethos. We’re a Silicon Valley Startup in Berlin - more here
  
  

Salary & Equity Ranges

Salary: 70,000 - 130,000 EUR

Equity: 0.25% - 0.75% Equity