About Summation
Summation is building an AI Business Planning Platform for CFOs and finance teams. We combine a real-time modeling layer with Addison, our AI calculation engine, to turn messy enterprise data into decision-grade insights. Customers use Summation to model scenarios, explain variances, and automate weekly and monthly reviews.
The Role
Design Engineering at Summation lives at the intersection of product design and frontend engineering. As a Senior Design Engineer, you will ship beautiful, high-performance product experiences in production code, lead our design system, prototype new interactions, and raise the bar on accessibility, motion, and polish. You will partner closely with Product, Design, and Engineering, moving from Figma to code to shipped features.
Roles & Responsibilities
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
You will love this role if you
Love working across design and code, and care about the details users feel
Think in systems: tokens, states, variants, docs, upgrade paths
Prototype ideas fast and are comfortable deleting code after an experiment
Believe accessibility, performance, and clarity are product features
Enjoy collaborating with PMs, designers, and backend engineers in a high-context startup
Required experience
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