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Senior/Staff React Frontend Engineer

Nuclearn

Nuclearn

Software Engineering
Phoenix, AZ, USA
Posted on Nov 25, 2025

Senior/Staff React Frontend Engineer

Why Nuclearn.ai

Nuclearn.ai builds AI-powered software for the nuclear and utility industries—tools that keep critical infrastructure reliable, efficient, and safe. Our software integrates AI-driven workflow, documentation, and research automation, and is already used at 60+ nuclear reactors across North America. You'll ship production code operators and engineers rely on every day.

We're growing quickly, expanding our team and our Phoenix HQ. The work is consequential: what you build helps real plants run safer and smarter.

Eligibility: U.S. citizenship or permanent residency (green card) is required due to DOE export compliance.

What You’ll Do

  • Architect scalable frontend systems that handle complex data workflows and real-time updates
  • Build sophisticated data visualizations that make ML model outputs interpretable and actionable
  • Design and implement component libraries that balance flexibility with consistency
  • Optimize performance for data-heavy applications while maintaining excellent UX
  • Collaborate deeply with backend engineers, data scientists, and domain experts to translate complex requirements into elegant interfaces
  • Establish frontend standards and drive technical decisions across the engineering team
  • Mentor engineers and elevate the entire team's frontend capabilities
  • Ship features end-to-end from concept to production, owning the quality and user experience

Examples of problems you might own in your first 90 days

  • Building real-time monitoring interfaces used in mission-critical nuclear operations
  • Designing complex, high-dimensional ML visualization components that make automated insights actionable
  • Establishing a robust frontend architecture and shared component system that scales with the engineering team

What Makes You a Great Fit

Technical Excellence

  • 7+ years building production web applications with deep expertise in React and modern JavaScript/TypeScript
  • Mastery of state management patterns (Redux, Zustand, React Query, Context, etc.)
  • Strong computer science fundamentals, including performance optimization and debugging complex systems
  • Experience architecting large-scale applications designed for long-term maintainability
  • Proficiency with modern tooling (Vite/Webpack, testing frameworks, CI/CD)

Product Mindset

  • You think beyond implementation—asking why and should we as often as how
  • Experience collaborating with designers, or designing interfaces yourself when needed
  • Track record of creating intuitive, delightful user experiences
  • Comfortable making pragmatic tradeoffs in ambiguous and fast-changing environments

Communication & Leadership

  • Ability to explain complex technical decisions to non-technical stakeholder
  • Experience mentoring engineers and performing thoughtful code reviews
  • Skilled at driving consensus and influencing technical direction
  • Thrive in a collaborative, fast-paced startup environment

Self-Directed Impact

  • Able to contribute independently within 6 weeks
  • High degree of ownership and ability to drive problems end-to-end
  • Proactively identifies improvements and executes on them

Nice To Have (not Required)

  • Experience with data visualization libraries (D3.js, Recharts, Plotly, etc.)
  • Background in complex domains (scientific, industrial, financial, healthcare)
  • Contributions to open source or technical writing
  • Experience with WebGL, Canvas, or high-performance graphics
  • Knowledge of accessibility (WCAG) and building inclusive interfaces
  • Full-stack capabilities or strong understanding of backend systems
  • Prior startup experience or leading engineering initiatives

Impact You’ll Have (near-term roadmap)

  • Improve the reliability and usability of interfaces used daily at nuclear power plants
  • Shape the foundation of our shared component library & frontend patterns
  • Lead development of new visualization systems for ML-driven analysis and operator workflows

Work Model & Schedule

  • Full-time, salaried
  • Mon–Fri hybrid (Wed remote); expectation is ≥80% in-office (Phoenix HQ)

How We Hire (fast, respectful, practical)

  1. 20-min intro with the founder/hiring manager to trade context and assess mutual fit
  2. Practical work sample (60–90 min; a real task in our stack)
  3. Team meet + peer programming (system design + collaboration)
    We aim to move from first chat to decision quickly.