Senior Design Engineer (Frontend-Heavy · Full-Stack Capable) in London

The highest calling for AI is improving human health. At Perceptic, we're building the AI operating system that powers drug discovery - a unified intelligence layer that connects evidence, reasoning, and action across the entire drug lifecycle. We were built by operators from Palantir who spent years deploying production AI in the world's most demanding enterprise environments. We know what it takes to make ambitious technology hold up under real pressure. Now we're applying that to pharma and we're hiring engineers who've operated at the same standard.

We're hiring a Senior Design Engineer who builds at the seam between design and engineering: roughly 80% frontend, 20% backend. You design in code, and you don't wait for a pixel-perfect spec. You take a rough sketch and make it feel right. This matters more here than in most places. Our users are scientists making high-consequence calls on the back of AI reasoning, and the interface is where they decide whether to trust it. A chain of agentic reasoning either becomes something a scientist can follow and verify, or it stays a black box they shouldn't act on, and the quality of the interface decides which one it is.

What you'll own:

• The look, feel, and interaction quality of the product end to end, from first interactive prototype to shipped, production-grade UI.
• Interfaces that make AI scientific reasoning legible and trustworthy, surfacing provenance, citations, and confidence as first-class parts of the UI.
• The craft of streaming AI: agent runs that unfold live, partial states, tool calls, and reasoning steps, which are the interaction problems most teams get wrong.
• A design system and component library that scales across the platform, so quality compounds over time.
• Prototyping at every fidelity, from sketch to interactive prototype to shipped feature, working directly with founders and engineers and skipping the static handoff.
• Motion, micro-interactions, latency, and perceived performance: how the app feels under production data and heavy load.
• The 20% backend: API and data-fetching layers, light services, and enough backend fluency to ship a whole feature on your own.

What we're looking for:

• At least 4 years of professional engineering experience, frontend-heavy with broad full-stack range.
• You've shipped polished, production AI or product UIs that people depend on, and you can talk concretely about the UX of building with language models: streaming, latency, partial states, failure modes, trust, and cost.
• Deep frontend craft across React/TypeScript, modern CSS, accessibility, animation, and performance. You sweat the details others skip.
• A strong design sensibility for typography, layout, hierarchy, color, and interaction. You can take a loose idea to something considered without a designer specifying every state.
• You've built or owned a design system and understand component APIs as a product.
• Fluent in both Figma and code, and comfortable being the person who closes the gap between them.
• You use AI coding tools fluently and have clear opinions about where they accelerate craft and where they get in the way.
• You've come from somewhere that held a high bar, such as FAANG, a top AI lab, or a respected product-engineering environment.
• You want more ownership, speed, and upside than those places offer, with the product taste and judgment to make pragmatic calls without perfect requirements.

This is a high-intensity, high-stakes role. We move quickly and give direct feedback, the responsibility you carry will likely outrun your title, and you'll go wherever the company needs you most, which sometimes means unglamorous work that matters more than anything else that week. The people who do well here find that kind of ownership and growth exciting, and they weren't looking for a nine-to-five.