Senior Design Engineer

The role

A Senior Design Engineer will build production UI in React and TypeScript and lead the Summation Design System. You will prototype product ideas, craft motion and micro-interactions, and partner with Product, Design, and Engineering teams.

What you will do

• Build production UI in React and TypeScript for Summation’s web app
• Lead the Summation Design System: tokens, components, theming, accessibility, docs, and release workflow
• Prototype end-to-end product ideas in code, validate with real data, and graduate winners into production
• Craft motion and micro-interactions that clarify meaning and reduce cognitive load
• Translate flows and states from Figma into resilient, testable components with strong state management
• Drive UI performance: bundle hygiene, code-split plans, rendering strategy, perceived latency
• Partner with data visualization to express complex financial concepts with clarity
• Establish guardrails: lint rules, Storybook checks, accessibility checks, visual regression in CI
• Mentor engineers and designers on interaction patterns, system thinking, and front-of-frontend craft
• Contribute to product quality across the stack through reviews, pairing, and high-signal documentation

Required qualifications

• 4+ years building production web UI with React and TypeScript
• Strong CSS fundamentals: layout, fluid type and spacing, responsive systems, motion
• Design system experience: tokens, component architecture, Storybook, documentation
• Data visualization in production using one of Recharts, D3, Visx, ECharts, or similar
• Accessibility and quality: semantic HTML, WCAG basics, keyboard and screen reader support, automated checks
• Figma fluency: components, variants, auto-layout, dev mode, and handoff
• Proven ability to take a concept from Figma to shipped code without heavy PM overhead

Nice to have

• Remix or Next.js, Tailwind, shadcn/ui
• Framer Motion for interaction design
• WebGL or Canvas experience for advanced interactions
• Visual regression and accessibility tooling in CI
• Experience in fintech, analytics, or complex data products

About the company

Summation is building an AI Business Planning Platform for CFOs and finance teams. They combine a real-time modeling layer with Addison, their AI calculation engine, to turn messy enterprise data into decision-grade insights.