Senior Frontend Engineer – HIRING ASAP

Start date: ASAP
Duration: 3-month contract
Location: Hybrid working in London office
Rate: £450 - £500 per day outside IR35

Summary

We're looking fora frontend engineer hire to own the client-side of our client’s stack. You'll work directly with their founding engineer (AI/ML background, leading backend, and model architecture) to build a polished, performant user experience that brings powerful AI capabilities into Excel.

Responsibilities
  • Own the frontend stack - Design and implement features across our Excel add-in and web platform using React and Next.js
  • Build AI-powered interfaces - Create intuitive UIs that make complex AI functionality accessible to non-technical users.
  • Establish frontend standards - Design our component architecture, state management patterns, and testing practices.
  • Integrate with AI services - Work closely with Vertex AI and other ML services to deliver responsive, intelligent features.
  • Shape the product - Work directly with founders and early customers to iterate rapidly on product direction.
  • Scale with us - Grow into a leadership role, eventually hiring and mentoring frontend engineers as the team expands.
Key Skills
  • 4-6 years of professional TypeScript experience - You write clean, maintainable TypeScript and understand its type of system deeply.
  • Strong React and Next.js expertise - Modern React patterns, hooks, performance optimization Production experience - You've shipped features to real users and dealt with the challenges that come with that.
  • Product mindset - You care about user experience and can balance technical excellence with shipping quickly.
  • Collaborative spirit - Comfortable working closely with a technical co-founder and giving/receiving feedback.
Nice to have
  • Experience with Next.js (App Router, server components)
  • Familiarity with AWS and Terraform for infrastructure.
  • Knowledge of monorepo tools (Turborepo, pnpm)
  • Previous AI integration work (API design for LLMs, streaming responses, etc.)
  • Experience building add-ins or browser extensions.
  • Interest in accounting/nance domains