Senior Software Engineer, Frontend

What we’re building ** Respan** is building the self-driving observability and evals platform for AI teams, used by 60+ YC companies and hundreds of AI teams. The role You will own the frontend architecture of Respan's platform: trace visualizers, eval dashboards, prompt editors, and the design system that ties it all together. This is a senior role with real architectural ownership. We are looking for someone who is opinionated about code quality, focused on performance, and can mentor the team on frontend best practices while still shipping fast. What you’ll do: Architect and build high-performance UI with React and Next.js Own the frontend architecture, component library, and design system Collaborate closely with design to ship pixel-perfect, accessible interfaces Mentor other engineers on frontend best practices and code quality Drive performance optimization across the platform UI What you must have: 5+ years of frontend engineering experience with TypeScript and React Deep knowledge of modern CSS, layout systems, and animation Strong opinions on code quality, testing, and component architecture Strong plus: Experience building complex data-heavy UIs such as dashboards, editors, or visualizers Track record of building and maintaining design systems Experience with performance profiling and optimization Contributions to open-source frontend projects or libraries