Senior UI Engineer (React & Design Systems)

Location: Milwaukee, Wisconsin, United States

Salary: $124,800–$137,300 per year

Company

hirify.global provides staffing and temporary professional engagements.

What you will do

• Build, extend, and harden reusable React and TypeScript components for a shared design system.
• Implement complex user interfaces and workflows using REST and streaming APIs, including data fetching, caching, and degraded-connectivity states.
• Ensure consistent UI behavior across edge, on-premises, and cloud deployments, supported browsers, and screen sizes.
• Write unit, component, and end-to-end tests using Jest or Vitest and React Testing Library.
• Diagnose and resolve performance issues involving bundle size, rendering cost, large datasets, and memory retention.
• Participate in Agile delivery, defect resolution, documentation, and handover to the permanent engineering team.

Requirements

• Bachelor’s degree in Computer Science, Software Engineering, or a related technical field, or equivalent professional experience.
• At least 4 years of experience building production web frontends.
• Deep expertise in React and TypeScript, including hooks, component composition, state management, and rendering behavior.
• Strong knowledge of modern HTML and CSS, responsive layouts, theming, CSS modules, or CSS-in-JS.
• Experience building or extending reusable component libraries or design systems used by multiple applications.
• Strong debugging, performance analysis, CI/CD, automated testing, code review, and cross-platform development skills.

Nice to have

• Experience implementing WCAG 2.1 AA accessibility standards, ARIA patterns, and keyboard-only navigation.
• Backend integration experience with Node.js/BFF or .NET/C#, plus Angular familiarity.
• Experience with real-time or high-frequency data streams, WebSockets or SSE, virtualized tables, or time-series charting.
• Experience developing, testing, and publishing Chrome or Edge browser extensions.
• Background in industrial control, IoT, operational technology, or complex enterprise SaaS platforms.

Culture & Benefits

• Six-month strategic engagement within an established Agile Scrum team using three-week sprints.
• Collaboration with permanent engineering staff and structured handover documentation.
• For temporary assignments lasting 13 weeks or longer: major medical, dental, vision, 401(k), and statutory sick pay where required.
• Reasonable accommodations are available during the employment process.