React Frontend Developer Jobs in California (NOW HIRING)

What We Believe

How we work is as important as what we build.

• Ownership is taken, not given. You’ll thrive here if your work builds others’ trust in your ability to identify, attack, and solve increasingly complex problems - including those no one has yet anticipated.
  
• Code wins arguments. We believe in prototyping early and often, and that shipping velocity compounds impact.
  
• We value speed and reflection. Some days, you’ll push thousands of lines of code; others, you’ll delete just as many after deep consideration.
  
• Failure is part of learning. You’re not afraid to build systems that don’t work out  - because you know progress often comes from what we throw away.
  
• Intellectual honesty is non-negotiable. You love to learn, teach, ask questions, and share uncertainty openly.
  
• We embrace the new frontier. You’re eager to explore how AI tools -  including agents -  can augment human creativity, collaboration, and craftsmanship.
  

The Opportunity

We are looking for a Full Stack Frontend Engineer to lead the development of high-performance, elegant, and intelligent user experiences for our AI-powered web applications. Reporting to the Director of ML & Platform Engineering, the Senior Frontend Engineer will collaborate closely with product, design, and AI research teams to bring cutting-edge ideas to life - building intuitive interfaces that redefine how people interact with intelligent systems.

What you’ll do

• Own end-to-end development of highly interactive, performant and elegant frontend experiences for our AI-powered web applications, from concept to production.
  
• Collaborate with product and design teams to translate ambiguous ideas into polished, user-friendly interfaces.
  
• Make thoughtful trade-offs between functionality, polish, and delivery speed -  always ship features fast to validate user value quickly at the forefront.
  
• Set the standard for clean, maintainable, and scalable frontend architecture.
  
• Integrate AI capabilities into seamless, human-centered user interactions.
  
• Implement analytics and feedback loops to measure impact and guide iteration.
  
• Optimize performance and reliability through strong CI/CD practices and frontend testing frameworks.
  
• Evolve our design system and component library to ensure consistency, scalability, and rapid product development.
  

Example Impact in First 30 Days

• Prototype an AI-assisted interaction pattern (e.g. inline agent suggestions, reasoning, errors, conversational shortcuts, or visualizations) and get it in front of users early.
  
• Reduce frontend load time by 40%.
  
• Establish frontend event tracking pipelines with clear naming conventions and dashboards.
  
• Refine design system/component library that accelerates product velocity across teams.
  
• Contribute to CI/CD pipeline to make it safer and faster to ship.
  

What we’re looking for

• Deep Frontend Expertise:
  
• Mastery of React, TypeScript, Next.js, TailwindCSS (or similar frameworks).
  
• Strong understanding of performance optimization, accessibility, and responsive design.
  
• Systems Thinker:
  
• Able to architect frontend systems that scale, modularize, and anticipate future needs.
  
• Understands the trade-offs between speed and structure — and knows when to optimize for each.
  
• AI Product Enthusiasm:
  
• Excited by AI-native interfaces, real-time interactions, and integrating LLMs or agentic workflows into user experiences.
  
• Eager to learn and experiment with new tools, pushing the boundaries of how people interact with intelligent systems.
  
• Speed & Impact:
  
• Proven ability to ship meaningful products quickly.
  
• Thinks analytically about product analytics and impact, instrumenting features to learn and iterate faster.
  
• Design Sensibility:
  
• A close collaborator with designers — someone who sweats the details of interaction, motion, and polish.
  
• Builds interfaces that are as delightful as they are functional.
  

Additional Kudos if you have

• Full-Stack Fluency: Comfortable dipping into backend services (Node.js, python), databases and search indexes when needed.
  
• Startup DNA:
  
• You've scaled products fast and are eager to do it again.
  
• Bias for action, ownership, and curiosity.
  
• Thrives in ambiguity, takes initiative, and grows the scope of what you can own over time.
  
• Communicates clearly - in writing, in code, and in collaboration.
  

Why Join Us?

• Opportunity to shape the frontend vision of cutting-edge AI products used by global customers.
  
• Small, senior team - work alongside exceptional engineers, product leaders, and AI researchers.
  
• High impact - every line of code you ship directly shapes the user experience.
  
• High ownership with growth opportunities.
  
• Competitive compensation including Benefits and Equity Package.
  
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Arrow BI and our clients are equal opportunity employers. We celebrate diversity and are committed to creating an inclusive environment for all innovators.