As the first dedicated UX Engineer at StackOne, you will be the internal authority on product polish and performance. You’ll own the design system, architect micro-frontends, and bridge the gap between design and engineering. Your work will directly impact how enterprise B2B customers interact with high-scale integration infrastructure and AI agentic workflows.
Senior UX Engineer at StackOne
StackOne is building the universal integration layer for B2B SaaS, and they need a Senior UX Engineer to lead the charge. You will work directly with the founding team to bridge the gap between technical excellence and world-class product experience. If you are a React expert with a passion for performance, polish, and shaping the future of AI-driven workflows, this is the career-defining role you have been looking for.
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Location
London, United Kingdom
Compensation
Not Disclosed + Equity
Company
StackOne
Role overview
SoftwareCanterbury, United KingdomSeries A (VC-backed)
StackOne is the AI Integration Gateway for SaaS products and AI Agents. With operations in the UK and US, the company enables builders of SaaS platforms and AI Agents to orchestrate hundreds of scalable, accurate, and enterprise-grade integrations. Their platform combines 25,000 pre-mapped actions on 200 connectors, an AI-powered integration development toolkit, plus security by design: a real-time architecture, managed authentication and permissions, and end-to-end observability. The company was founded by a team of former Google, Oracle, JP Morgan, Coinbase, and Microsoft employees with a mission to build the most advanced integration infrastructure for generative AI applications. StackOne has experienced rapid growth, serving enterprise clients globally, and is backed by notable investors, including GV (Google Ventures), Workday Ventures, and Episode 1.
Backed by GV (Google Ventures), Workday Ventures, XTX Ventures, Episode 1 Ventures, Playfair Capital, Founders of GitHub, Founders of Onfido, Founders of Hofy, Angel investors from OpenAI, Angel investors from Google DeepMind, Angel investors from Microsoft, Angel investors from MuleSoft.
What you will do
- Own the StackOne design system by building reusable primitives and maintaining component libraries that power the entire product suite.
- Optimize frontend performance by instrumenting Core Web Vitals, managing bundle sizes, and ensuring a median Time to Interactive under two seconds.
- Collaborate with founders and product teams to prototype new features and establish AI-driven rules that maintain high UI standards across the codebase.
Who this is a fit for
- Brings 4+ years of professional experience in React and TypeScript with a portfolio demonstrating exceptional visual craft and attention to detail.
- Demonstrates deep proficiency in modern CSS (Tailwind), design system architecture, and performance tuning tools like Lighthouse and bundle analysis.
- Possesses a founder’s mindset with the ability to navigate Node.js backends and monorepo tooling like Nx or Turborepo to eliminate bottlenecks.
Why this role is remarkable
- Founding-level impact: You are the first dedicated UX hire, responsible for setting the visual language and engineering standards for the entire frontend ecosystem.
- Elite backing: Work for a high-growth Series B company backed by top-tier investors including Google Ventures (GV) and Workday Ventures.
- Scale and Innovation: Build the critical infrastructure powering integrations for global SaaS leaders like Drata, while defining how AI agents interact with user interfaces.
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I get to know what you’re great at, then find roles you’d never find yourself.Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
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