Shape the design system behind a unicorn AI-native SaaS platform, scaling globally at speed.
Why This Role?
Stax is partnering with a unicorn AI-native SaaS scale-up that’s transforming how organisations use AI. Now they’re building a London engineering hub. Join as a UK founding engineer - hybrid working, high impact, and the chance to shape a category-defining platform from day one.
The Opportunity
This is a systems-level role at the intersection of design and engineering. You’ll be at the heart of a platform that’s changing how organisations use AI for customer support and product operations.
In just four years, the team has:
* Pushed browser limits with D3-powered visualisations and real-time dashboards
* Open-sourced client-side analytics on DuckDB, bringing OLAP to the edge
* Built AI-native UIs that feel fast, intelligent, and fun
* Scaled a themeable design system adopted across multiple products and platforms
* Introduced micro-frontends that power independent, high-velocity teams—and let customers embed their own modules directly in the product
* Delivered deeply configurable UIs where layouts, components, and visualisations can be reshaped end-to-end via declarative config
Your role: define the system that makes every pixel seamless, scalable, and lightning-fast.
What You’ll Do
* Evolve the design system: tokens, theming, accessibility, visual language
* Build React + Web Component libraries for core + embedded apps
* Advance tooling: Storybook, Chromatic, Figma plugins
* Set standards and governance across design + engineering
* Deliver performant layouts and visualisations at scale
* Mentor peers on accessibility and performance-first development
Tech Ecosystem You’ll Shape
Design Tokens · Figma API · Storybook · React · Web Components · TypeScript · Tailwind CSS · Vite · NextJS · Jest · Cypress · Playwright
What You Bring
* 8+ years in large-scale web apps, 2+ in design-system architecture
* Strong perspective on tokens, theming, multi-brand support
* Mastery of React + TypeScript, with library publishing experience
* Accessibility leadership (WCAG, ARIA, keyboard nav, colour contrast)
* Fluency in CSS methodologies and testing frameworks
* Excellent communication skills to align design, product, and engineering
* Bonus points for OSS contributions, Figma plugins, or micro-frontend orchestration
Culture & Impact
* Speed with craftsmanship: fast feedback, continuous delivery, peer reviews
* Performance-first mindset: Core Web Vitals as product metrics
* Inclusive and global: teams across the US, Europe, and India
* Autonomy with accountability: design, guide, measure, iterate
* London hub: hybrid model, build the team and culture from the ground up
Why join?
Your design system will power products used by some of the world’s most ambitious teams. Join at a moment of hyper-growth and play a defining role in one of the most exciting SaaS platforms in the world.
Stax welcomes applications from all backgrounds. Our client unfortunately can't offer visa sponsorship.