Senior Frontend Engineer

Overview

About the Role Thousands of engineers sign in daily to inspect traces, update prompts, and run experiments on an open-source LLM engineering platform, think Datadog, but for AI observability. Full LLM inputs and outputs can span 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 sta

What you'll do

• About the Role Thousands of engineers sign in daily to inspect traces, update prompts, and run experiments on an open-source LLM engineering platform, think Datadog, but for AI observability.
• Full LLM inputs and outputs can span 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 state.
• The data is massive, the interface should never feel like it is.
• This is a high-ownership, senior-level role on a small, remote-first European engineering team with meaningful cross-functional collaboration.
• What You'll Do Build performant trace views, Own rendering of large LLM data: identify bottlenecks, optimize data loading, reduce re-renders so even the largest agent traces feel snappy.
• Own the React architecture, Shape how components are built, code is structured, and tests are written.
• Keep the codebase current with React Compiler and emerging patterns.

Requirements

• Practical experience with Engineering.
• Experience level: 5+ yrs.
• Strong written and verbal communication in English.
• Comfortable working on-site in Berlin.

Skills