Senior Frontend Engineer
Germany +8 Ā· Hybrid$90k ā $160k
About this role
The Role
Make megabytes of LLM data
feel instant and obvious.
feel instant and obvious.
Thousands of engineers sign into Langfuse daily to inspect traces, update prompts, and run experiments. Full LLM inputs and outputs can be tens of thousands of tokens. Your job: make that experience fast and intuitive.
You love profiling React renders. You know when to virtualize, memoize, or restructure. The data is massive ā the interface should never feel like it is.
About Langfuse
Open Source LLM Engineering Platform ā the Datadog of AI observability. Trusted by 19 of the Fortune 50, 2k+ customers, 26M+ monthly SDK downloads. Now part of ClickHouse.
What You'll Do
01
Build performant trace views ā Own rendering of large LLM data: bottlenecks, data loading, re-render reduction so even the largest agent traces feel snappy.
02
Own our React setup ā Shape how we build components, structure code, and write tests. Keep us up to date with React Compiler and new patterns.
03
Ship complex interactive features ā Recent examples: agent graph visualization, redesigned trace view with tree/timeline toggle, inline comments anchored to text selections.
04
Ship end-to-end ā Connect to tRPC APIs and extend them when a feature needs it. No hard boundaries.
What We're Looking For
- Senior frontend engineer obsessed with performance ā you profile renders, know when to virtualize, memoize, or restructure
- Strong in React, TypeScript, and modern CSS
- Can manage yourself ā strong opinions about what to build and how to ship it
- Genuinely enjoys talking to users about their experience
- CS or quantitative degree preferred
Bonus: large data application experience, former founder, data visualization or devtools background
Salary
ā¬90,000 ā ā¬160,000
Location
Remote EU Ā· 1 week/month Berlin
Type
Full-time
Process
Offer in < 7 days
Company at a glance
Langfuse is an open-source LLM engineering platform that helps teams build production-grade LLM applications faster, and it is used by thousands of teams worldwide.
IndustryAI/ML
Team Size11-50
WorkspaceHybrid
StageSeed
Founded2022
Locations
Germany Ā·Austria Ā·Switzerland Ā·United Kingdom Ā·Netherlands Ā·France Ā·Spain Ā·Sweden Ā·Poland
Investors
La Famiglia Ā·Lightspeed Venture Partners Ā·Y Combinator
Websitelangfuse.com
LinkedInLinkedIn
Know someone who'd be great for this?
