Senior Front End Engineer

Blitzy•Cambridge, MA

9d•$150,000 - $185,000•Onsite

About The Position

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 at Blitzy. You’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.

Requirements

10+ years of frontend development experience with a proven track record of building complex, production-grade applications.
Expert-level knowledge of modern JavaScript/TypeScript with deep understanding of language features, patterns, and best practices.
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.
Experience with responsive design and cross-browser compatibility, ensuring consistent experiences across devices.
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 working effectively with AI coding tools (Blitzy, Copilot, Cursor, Claude, etc.) to accelerate frontend development without compromising code quality or engineering standards.
Proven ability to review and validate AI-generated code—identifying subtle logic errors, security gaps, and style inconsistencies that automated tools routinely miss.
Track record of writing precise, reusable prompts for frontend tasks including component generation, test writing, refactoring, and PR documentation to get consistent, production-ready output.
Experience establishing team-wide processes for AI-assisted development—defining when to use AI, how to review its output, and how to integrate it cleanly into existing PR and code review workflows.

Nice To Haves

Experience with GraphQL and real-time data handling (WebSockets, Server-Sent Events).
Knowledge of WebAssembly and its applications in frontend development.
Experience with micro-frontend architectures or monorepo management.
Contributions to open-source projects, especially in the React or JavaScript ecosystem.
Experience with advanced animations and complex UI interactions (Framer Motion, React Spring).
Deep knowledge of accessibility standards (WCAG) and practical implementation.
Experience with design systems at scale and component library architecture.
Speaking engagements or technical writing demonstrating thought leadership.
Experience at high-growth startups or in technical leadership roles.

Responsibilities

Architect and implement sophisticated frontend solutions that handle complex state management, real-time AI agent updates, and intuitive developer workflows.
Establish frontend engineering standards, patterns, and best practices that scale with our growing team.
Build responsive, performant interfaces that work seamlessly across browsers and devices while maintaining sub-second interaction speeds.
Refactor and modernize existing frontend code, eliminating technical debt while shipping new features.
Make architectural decisions that balance immediate product needs with long-term scalability and maintainability.
Mentor junior frontend engineers, conducting code reviews and elevating the team’s technical capabilities.
Collaborate closely with product, design, and backend teams to deliver cohesive user experiences.
Evaluate and introduce new technologies and frameworks that improve our development velocity and product quality.
Maintain high standards for code quality, performance, testing, and accessibility.
Become a trusted technical advisor to leadership on all frontend architecture decisions.
Own frontend architecture and technical decision-making for our core platform.
Refactor existing frontend systems to improve performance and maintainability.
Build new platform features that showcase our AI capabilities to enterprise users.
Establish component library and design system foundations.
Set up testing frameworks and CI/CD pipelines for frontend.
Oversee code review processes and engineering standards.
Mentor and provide technical guidance to junior frontend engineers.
Drive performance optimization and monitoring systems.
Improve frontend infrastructure and build tooling.
Collaborate cross-team on API design and integration patterns.
Develop technical documentation and onboarding processes.
Scale the frontend engineering team and practices.
Define frontend engineering hiring standards and interview processes.
Contribute to product and technical strategy discussions.
Build advanced features like real-time collaboration, AI-powered UIs, and developer tools.