Lead Product Engineer
Lead Product Engineer | AI Platform | London Hybrid | £120,000–£140,000 + Share Options
I’m working with a profitable, fast-growing technology company building an AI-powered research platform that is changing how organisations move from questions to decisions.
They already work with major global brands, charities and institutions, and are now looking for a Lead Product Engineer to help shape the technical direction of a platform expected to become a major part of the business over the coming years.
This is a senior individual contributor role, not a people-management position. You’ll work alongside other Lead Engineers, stay deeply hands-on in the codebase, and help make the architectural and product decisions that compound over time.
It’s a brilliant opportunity for someone who could plausibly be a founding engineer elsewhere, but wants the scope, autonomy and pace of an early-stage environment without starting from scratch.
What you’ll be doing:
• Shipping production code daily across backend, frontend and AI systems
• Designing and building the most complex parts of the platform yourself
• Shaping architecture across services, agent workflows, data models and user-facing product surfaces
• Driving the technical roadmap over the next 12–24 months
• Leading the design of production LLM systems, including evals, retrieval, agent orchestration, prompts and tool use
• Setting the standard for engineering quality, testing, code review, deployment and observability
• Working directly with customers to understand problems and shape solutions
• Mentoring engineers through code reviews, technical discussions and hands-on collaboration
• Making pragmatic architectural decisions around complexity, scale and long-term maintainability
Tech stack:
Python, FastAPI, LangGraph, Redis, PostgreSQL, Neo4j, React, TypeScript, Kubernetes, GCP and Datadog.
What they’re looking for:
• Roughly 7+ years of engineering experience, although what you’ve shipped matters more than years
• Strong full-stack engineering capability with real backend depth
• Fluency in Python or a closely related backend language
• Experience designing systems with genuine complexity, including queues, async workflows, durable state and production-grade observability
• Hands-on experience building and operating LLM-based products in production
• Strong experience with evals, agentic systems, RAG, prompt design and tool use
• A proven ability to make architectural decisions and explain the trade-offs behind them
• Experience helping shape engineering culture, including testing standards, review practices and CI/CD
• A startup mindset and comfort working in fast-moving, ambiguous environments
• Strong communication skills and confidence engaging directly with customers
Bonus points:
• Founder or early-engineer experience
• Experience joining a company within the first 10 engineering hires
• Production experience with agentic systems or RAG at scale
• Open-source contributions
• Exposure to market research, survey methodology or data-heavy products
Package:
• £120,000–£140,000 base salary
• Share options
• Private healthcare
• Pension
• 25 days annual leave
• Cycle to Work scheme
• Laptop and equipment budget
• Bright Spitalfields office
• Hybrid working in London
This is a rare opportunity for a hands-on senior IC who wants to shape architecture, influence product direction and build production AI systems with real customer impact.
Apply if you’d like to hear more.