Senior Frontend React Developer

As a Frontend Engineer, you will craft interfaces that make enterprise AI accessible and trustworthy, building production-ready Next.js applications that handle high-load scenarios, complex states, and real-time AI streaming. You will design and implement scalable SSR applications used by thousands of enterprise users, ensuring performance, accessibility, localization, and security compliance.

Responsibilities

• Design and implement production-ready Next.js SSR applications with complex state management and real-time AI interactions at scale
• Build interfaces for AI-powered features including streaming LLM responses, semantic search, interactive knowledge graphs, intelligent content recommendations, and AI agent builders
• Architect component libraries and maintain the design system in Storybook, ensuring reusability and accessibility
• Develop enterprise-grade functionality including multi-language support, accessibility compliance, cross-browser compatibility, and SOC 2–aligned security implementations
• Create technical specifications and component API designs
• Build and optimize data-heavy UIs using React Flow, Highcharts, and custom virtualization
• Instrument components for performance monitoring, track Core Web Vitals, implement error boundaries, and create automated visual regression tests with Playwright
• Optimize bundle sizes and ensure scalability under growing user load
• Work with SWR for data fetching, caching, and revalidation
• Integrate with backend services via REST APIs and WebSockets, implementing optimistic UI patterns
• Leverage AI coding assistants and contribute to internal AI agents for frontend workflows
• Stay current with React and Next.js best practices and contribute to engineering standards

Requirements

• 5+ years of professional frontend engineering experience
• 3+ years specializing in React and modern JavaScript/TypeScript
• Production Next.js experience with SSR, app router, and rendering strategies (SSR, SSG, CSR)
• Deep TypeScript knowledge including generics and advanced typing patterns
• Experience with complex state management for real-time collaboration and multi-tenant systems
• Enterprise application experience including i18n, accessibility, and security best practices
• Experience building AI/LLM interfaces with streaming or real-time features
• Proven high-load performance optimization experience and Core Web Vitals monitoring
• Strong expertise in Tailwind CSS and/or CSS-in-JS
• Familiarity with observability tools such as Datadog or Sentry
• Experience with AI coding assistants
• Upper-Intermediate or higher English proficiency

Nice to Have

• Experience with React Flow, Highcharts, or advanced data visualization libraries
• Understanding of Node.js or Python backend fundamentals
• Experience with SWR or React Query
• Experience with vector search or RAG interfaces
• Familiarity with MCP, DSPy, or similar AI frameworks
• Experience with monorepo tools (Lerna, Turborepo, Nx)
• Knowledge of AWS services (S3, CloudFront, Lambda)
• Experience with Playwright, Puppeteer, or Cypress
• Experience building AI agent interfaces

What Shelf Offers

• B2B contract
• Company stock options
• MacBook Pro
• Modern technical stack
• Open-source development opportunities
• Access to AI development tools including GitHub Copilot, Claude Code, OpenAI Codex, TypingMind, v0, MCP Servers, and experimentation credits