Lead Full-Stack Engineer

CompanyComplexio

LocationLondon, England, United Kingdom

Posted At3/6/2026

UK Visa Sponsorship Analytics

Analytics are greyed out due to low classification confidence (45.0%).

Occupation Type

Programmers and software development professionals

Occupation Code Skill LevelHigher Skilled

Sponsorship Salary Threshold

£54,700 (£28.05 per hour)

Occupation rate applies

Above analytics are generated algorithmically based on job titles and may not always be the same as the company's job classification. You can also check detailed occupation eligibility, and salary criteria on our UK Visa Eligible Occupations & Salary Thresholds page.

Disclaimer: Hunt UK Visa Sponsors aggregates job listings from publicly available sources, such as search engines, to assist with your job hunting. We do not claim affiliation with Complexio. For the most up-to-date job details, please visit the official website by clicking "Apply Now."

Description

Complexio is building Stevie — an enterprise AI knowledge assistant that gives executives and operators a complete view of their organization through knowledge graphs. Our customers are large maritime shipping companies managing hundreds of vessels, thousands of daily emails, and complex commercial operations.

We're looking for a Senior or Lead Frontend Engineer to own Stevie's frontend. The interface is the product — it determines whether enterprise customers trust the intelligence, get value quickly, and come back. You'll shape all of that.

Why This Role

Enterprise AI UX is unsolved. You won't copy patterns — you'll create them. Citations from knowledge graphs, streaming AI responses that feel trustworthy, confidence indicators on operational intelligence.

You own the full frontend. No separate frontend team. You are it — with real influence on product direction and architectural decisions.

Flat org, real impact. Domain owners have authority. Engineering decisions are made by engineers, not managers.

You'll own the full frontend — conversational AI interfaces, content feeds, document generation, collaborative features. The product is evolving fast and you'll shape what gets built and how.

Requirements

Must-haves

5+ years of frontend experience in production. You understand rendering models, performance characteristics, and architectural patterns deeply.

Strong product sense. You push back when the UX doesn't make sense. You've shipped real user-facing products
Real-time/streaming UI experience. WebSockets, SSE, or similar live data patterns
Comfort with ambiguity. You take vague problems and turn them into concrete frontend solutions
You ship. End-to-end — prototype to production to iteration on feedback

Strong signals

Enterprise/B2B SaaS. You know the difference between consumer UX and building for a CFO who needs to trust a number
AI product experience. Latency UX, citation rendering, hallucination presentation
Design sensibility. Polished interfaces without a designer in the room
Backend literacy. You can read a REST API and collaborate with backend engineers on data contracts
Startup experience. Small teams, multiple hats, fast without cutting corners

How We Work

Direct communication. Honest feedback, hard questions, no hiding behind process

Ownership over tasks. You're asked what you shipped and learned, not to fill out status reports

Speed with quality. We ship fast because we scope well. Customer feedback cycles are weeks, not quarters

AI-augmented workflow. We use AI tools extensively and expect you to be comfortable with AI-assisted development