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