Senior Frontend Software Engineer - AI-Driven Applications

About the Role

We are seeking a Senior Frontend Software Engineer to join our team at Mission.dev. This role focuses on building high-performance, real-time web applications that serve as user interfaces for AI-driven developer and audit tooling. As a Senior Frontend Software Engineer, you will work closely with advanced backend AI systems to create intuitive interfaces that enhance user experience. This position is based in Palo Alto, California, and is not remote, but we offer relocation and visa support for the right candidate.

What You’ll Do

• Design and build complex frontend applications using TypeScript and React.
• Own frontend architecture decisions, including routing, state management, caching, and rendering strategies.
• Implement real-time UI patterns for AI systems, including streaming model outputs and live system feedback.
• Build and maintain reusable component systems and design tokens to ensure consistency across applications.
• Enforce accessibility, responsiveness, and cross-browser reliability in all projects.
• Develop rich interfaces for data review, annotation, and human-in-the-loop audit workflows.
• Instrument analytics, monitoring, and experiments to measure UX quality and performance.
• Partner closely with product, design, and backend teams to turn research and prototypes into production-ready experiences.

Requirements

• 5–8+ years of professional frontend engineering experience.
• Strong, production-level expertise with TypeScript and React (Next.js, Vite, or similar).
• Experience building and operating large, complex frontend applications.
• Recent hands-on experience with AI-enabled or agent-based systems, ideally in B2B environments.
• Deep understanding of frontend performance, reliability, and maintainability.
• Proven experience shipping real-time user interfaces connected to AI or streaming systems.
• Strong testing discipline, including automated testing (e.g., Playwright, Jest).
• Ability to remain hands-on while contributing to technical direction and mentoring others.

Nice to Have

• Ownership of frontend architecture or design systems at a SaaS or developer-focused company.
• Familiarity with modern API and data transport patterns (e.g., GraphQL, typed RPCs).
• Experience with advanced browser capabilities (e.g., web workers, WASM).
• Data visualization experience for technical or analytical users.

What We Offer

• Competitive compensation package.
• Healthcare coverage for you and your family.
• Equity participation in the company.
• Relocation and visa support for candidates moving to Palo Alto.
• A high-intensity, execution-focused engineering culture.
• Opportunities to work on foundational AI systems with significant technical depth.