Senior Frontend Engineer (Contract)

Contract Length: 3-6 months
Rate: £550 – £600 p/d
IR35 Status: Outside IR35
Location: Remote-first with occasional London visits

We’re supporting an AI product company building a highly interactive, browser-based collaborative platform used by creative and design-focused teams globally.

They’re looking for a Senior Frontend Engineer to help scale and evolve a complex frontend application that combines real-time collaboration, advanced rendering, multiplayer state management, and AI-powered workflows.

This is not a standard CRUD-style React contract.

The environment is heavily focused on frontend engineering quality, performance, interaction design, and solving technically challenging browser problems.

The Role

You’ll work closely with a small, high-calibre engineering team on a sophisticated web application that includes:

• Real-time collaborative experiences
• Advanced canvas-based interaction
• AI-assisted workflows
• Complex client-side state management
• Rich media and interactive rendering
• Performance-sensitive frontend systems

The product is evolving rapidly, so this role suits someone comfortable operating in fast-moving startup environments where ownership and engineering judgement matter.

Tech Environment

• React
• Next.js
• TypeScript
• WebSockets
• State management libraries (Zustand / Redux / MobX)
• WebGL / three.js
• react-three-fiber

What they’re looking for

• Strong commercial experience building complex frontend applications in React
• Experience with highly interactive or real-time web products
• Strong understanding of frontend performance optimisation
• Comfortable working with advanced client-side state management
• Experience working in product-led engineering teams
• Ability to contribute technically from day one with minimal oversight

Particularly interesting backgrounds

• Collaborative tooling
• Design platforms
• Browser-based creative applications
• Data visualisation products
• Real-time SaaS platforms
• Canvas-heavy or rendering-focused applications

Nice to have

• Experience with multiplayer / collaborative systems
• WebGL or 3D rendering exposure
• Experience building performance-sensitive browser applications
• Comfort contributing across the stack where needed