Senior Frontend Engineer

Location: 1 Kendall Square, Cambridge, MA (In-person role)

We're looking for an exceptional Senior Frontend Engineer to join our founding team and lead our frontend engineering efforts. You'll work directly with our CTO to build sophisticated, responsive interfaces that make complex AI capabilities accessible to enterprise developers. This is a hands‑on technical leadership role where you'll architect our frontend systems, establish engineering best practices, and mentor junior engineers as we scale.

You’ll be the frontend technical authority—making critical architectural decisions, building new platform features, refactoring existing systems, and defining how we approach frontend engineering ’re equally comfortable debugging a complex state management issue, architecting a component library from scratch, or mentoring a junior engineer through their first major feature.

• You architect and implement sophisticated frontend solutions that handle complex state management, real‑time AI agent updates, and intuitive developer workflows
• You establish frontend engineering standards, patterns, and best practices that scale with our growing team
• You refactor and modernize existing frontend code, eliminating technical debt while shipping new features
• You make architectural decisions that balance immediate product needs with long‑term scalability and maintainability
• You mentor junior frontend engineers, conducting code reviews and elevating the team’s technical capabilities
• You collaborate closely with product, design, and backend teams to deliver cohesive user experiences
• You evaluate and introduce new technologies and frameworks that improve our development velocity and product quality
• You maintain high standards for code quality, performance, testing, and accessibility
• You become a trusted technical advisor to leadership on all frontend architecture decisions

As our Senior Frontend Engineer and technical lead, you’ll own:

Immediate Priorities (0‑6 months)

• Frontend architecture and technical decision‑making for our core platform
• Refactoring existing frontend systems to improve performance and maintainability
• Building new platform features that showcase our AI capabilities to enterprise users
• Establishing component library and design system foundations
• Setting up testing frameworks and CI/CD pipelines for frontend
• Code review processes and engineering standards

Growing Responsibilities (6‑12 months)

• Mentoring and providing technical guidance to junior frontend engineers
• Performance optimization and monitoring systems
• Frontend infrastructure and build tooling improvements
• Cross‑team collaboration on API design and integration patterns
• Technical documentation and onboarding processes

Long‑term Vision (12+ months)

• Scaling the frontend engineering team and practices
• Defining frontend engineering hiring standards and interview processes
• Contributing to product and technical strategy discussions
• Building advanced features like real‑time collaboration, AI‑powered UIs, and developer tools

• 10+ years of frontend development experience with a proven track record of building complex, production‑grade applications
• Deep expertise in React.js and its ecosystem including hooks, context, performance optimization, and modern patterns
• Strong understanding of state management (Redux, MobX, Zustand, or similar) and when to apply different patterns
• Experience with modern build tools (Webpack, Vite, esbuild, etc.) and their configuration
• Proven ability to architect scalable frontend systems that handle complexity while remaining maintainable
• Strong understanding of web performance optimization including bundle size, rendering performance, and Core Web Vitals
• Experience with frontend testing frameworks and methodologies (Jest, React Testing Library, Playwright, Cypress)
• Track record of technical leadership including mentoring, code reviews, and establishing engineering standards

• Experience with Graph
  
  QL and real‑time data handling (Web Sockets, Server‑Sent Events)
• Knowledge of Web Assembly and its applications in frontend development
• Experience with micro‑frontend…