Primates.

Senior Frontend Engineer

Engineering San Francisco (Hybrid) Full-time
$160,000 - $220,000 USD Posted December 1, 2025

About the Role

We are looking for a Senior Frontend Engineer to join our core platform team and help shape the future of how developers interact with testing infrastructure. In this role, you will own significant portions of the Primates web application -- from the real-time test execution dashboard that processes thousands of concurrent test results, to the visual regression comparison interface that helps teams catch pixel-level UI regressions before they reach production. You will work closely with our design team to translate complex testing workflows into intuitive, performant user interfaces. Our frontend is built on React 18 with TypeScript, leveraging Next.js for server-side rendering and incremental static regeneration. We use Tailwind CSS for styling, Zustand for state management, and React Query for server state synchronization. The application communicates with our backend through a combination of REST APIs and WebSocket connections for real-time test streaming. The ideal candidate has deep expertise in modern React patterns including concurrent features, Suspense boundaries, and server components. You should be comfortable optimizing rendering performance for data-heavy interfaces -- our test results dashboard routinely displays thousands of rows with real-time status updates, and maintaining smooth 60fps interactions at that scale requires thoughtful virtualization and memoization strategies. You will also contribute to our open-source component library, which is used by both our internal application and by customers who embed Primates widgets into their own CI/CD dashboards. This means writing components that are not only functional but also thoroughly documented, accessible, and flexible enough to accommodate diverse integration scenarios. This is a hybrid role based in our San Francisco office, with the expectation of 3 days per week in-office. We believe that the complex, collaborative nature of frontend architecture work benefits from regular in-person interaction, while also recognizing that focused coding work is often best done from a quiet home environment. Our San Francisco office is located in the SoMa district, within walking distance of Caltrain and multiple BART stations.

Responsibilities

  • Architect and implement complex React interfaces for test execution monitoring, visual regression comparison, and analytics dashboards
  • Optimize frontend performance for data-intensive views displaying thousands of concurrent test results with real-time WebSocket updates
  • Lead the development and maintenance of our open-source React component library used by internal teams and external customers
  • Collaborate with product designers to translate wireframes and prototypes into polished, accessible user experiences
  • Mentor junior and mid-level frontend engineers through code reviews, pair programming, and technical design sessions
  • Establish and enforce frontend coding standards, testing practices, and architectural patterns across the engineering organization
  • Contribute to frontend build tooling, CI/CD pipeline optimization, and developer experience improvements
  • Participate in on-call rotation for frontend-related production incidents (approximately one week per quarter)

Requirements

Required

  • 7+ years of professional frontend development experience, with at least 4 years focused on React and TypeScript
  • Deep understanding of React rendering lifecycle, performance optimization techniques, and concurrent mode features
  • Experience building real-time interfaces using WebSockets, Server-Sent Events, or similar streaming protocols
  • Strong proficiency in modern CSS (Tailwind, CSS Grid, Flexbox) and responsive design for complex data-driven layouts
  • Track record of leading frontend architecture decisions on production applications serving 10,000+ daily active users
  • Experience with testing frameworks (Jest, Playwright, Cypress) and a commitment to writing testable, well-documented code
  • Excellent communication skills with the ability to articulate technical trade-offs to both engineering and product stakeholders

Preferred

  • Experience with Next.js App Router, React Server Components, and server-side rendering optimization
  • Contributions to open-source projects, particularly component libraries or design systems
  • Familiarity with WebGL or Canvas APIs for data visualization at scale
  • Experience with accessibility auditing tools (axe, Lighthouse) and WCAG 2.1 AA compliance
  • Background in developer tools, DevOps dashboards, or CI/CD user interfaces

Benefits

  • Competitive salary range of $160,000 - $220,000 plus equity (0.05% - 0.15% based on experience)
  • Comprehensive health, dental, and vision insurance with 100% premium coverage for employees
  • 401(k) with 4% company match, vested immediately
  • Unlimited PTO with a minimum of 15 days encouraged, plus 10 company holidays
  • Annual learning and development budget of $3,000 for conferences, courses, and books
  • Home office setup stipend of $2,000 for new hires
  • Commuter benefits for public transit and bike-to-work programs
  • Weekly catered lunches and fully stocked kitchen in the San Francisco office
  • 12 weeks paid parental leave for all new parents

Interested in this role?

We'd love to hear from you. Submit your application and our recruiting team will be in touch within 5 business days.

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