Senior Front-End Engineer

An early-stage open-source platform is building the feedback loop that powers smarter, faster, and more efficient large language model (LLM) applications turning real-world data into continuous improvements. What we're building: Seamless collection of metrics and feedback Optimization tools for prompts, models, and inference strategies Native experimentation and fallback support A data-and-learning flywheel for LLMs The platform brings together: Inference: One API to manage all LLMs with minimal latency overhead Observability: Inference data and user feedback fed directly into your systems Optimization: From prompt engineering to fine-tuning and reinforcement learning Experimentation: Built-in A/B testing, smart routing, and fallback capabilities The Role Were hiring a Founding Member of Technical Staff with expertise in front-end or design engineering. Why not just engineer? We encourage cross-functional ownership combining product thinking, research instincts, and technical craftsmanship. While we need help building user-facing tools now, the opportunity exists to contribute across the entire stack over time. Your first major project would likely be developing an open-source UI something like the console that ties everything together, making it easy for users to visualize and control model behavior, experimentation, and optimizations. We already collect plenty of observability data, but its waiting for the right person to design and build intuitive, delightful interfaces for it. What We Offer Highly competitive compensation (salary, equity, and benefits) The chance for your work to be open-source and highly visible Freedom to expand your skills into new areas whether infrastructure, machine learning, or beyond A small, focused, in-person environment where technical quality and craftsmanship matter Backing from world-class investors with a track record in AI, infrastructure, and developer tools What We're Looking For A strong technical foundation with the ability to lead and ship large projects (starting with the observability dashboard) Passion for building interfaces that not only work but truly delight developers Front-end engineering experience we're currently experimenting with Remix and Tailwind but need dedicated expertise (especially in React) Eagerness to learn and contribute across domains Willingness to work in person, five days a week, in New York City Very competetivesalary + meaningful equity + benefits #J-18808-Ljbffr