Full-Stack AI Engineer

Full-Stack AI Engineer · PE-backed AI startup · 4 days onsite in Holborn -£120K + equity

A general manager opens a coffee shop at 6am. The supplier hasn't delivered. Three of the morning rota have called in sick. The stock count from last night doesn't add up. Nobody has built software for this person.

The company is building it. At Pret A Manger alone, the platform is on track to save each general manager two hours every day, equivalent to $4m in annual savings.

The company

PE-backed AI startup rebuilding back-of-house operations for hospitality. Founded by an operator who scaled and sold a coffee chain to Blank Street in 2022. £3M seed round just closed , giving the team 4 years of runway on top of existing revenue.

Pret A Manger, Dunkin' Donuts, WatchHouse and Yolk Brands run their back of house on this platform across 6 countries.

AI is core to how the platform works. Not bolted on, not a feature. The intelligence layer is what makes the product. This role is about getting that intelligence into the product and in front of customers.

The Full Stack AI Engineer role - what you'll be doing:

• Shipping AI features end to end. Take features from prototype to production across the full stack (TypeScript, NestJS, React).
• Leading build-vs-buy and architecture calls. Pick the right managed model and pattern (RAG, agents, structured outputs, classification) balancing accuracy, latency, cost and data privacy.
• Making AI features production-grade. Own the eval harnesses, prompt versioning, observability, cost controls and guardrails that separate a demo from a product.
• Pull the context features need. Query the data warehouse for what each feature depends on and deploy into the existing microservices architecture.
• Keeping the team current. Stay close to the moving LLM and agent landscape to make sharp architecture and build-vs-buy calls.

Key people you'll be working with:

• A founder who built and exited a real hospitality business before this one
• A Principal Engineer, Imperial College-trained, 20+ years across startups and scale-ups
• A Tech Lead with a startup-to-acquisition track record
• A Senior Data Engineer with 6+ years building production pipelines for 1000+ retail outlets
• A Head of Product with 12 years across banking, healthcare and AI-powered product

Who they're looking for:

• A software engineer first, comfortable owning real production code - strong skills across their stack is the core requirement (Typescript, Node.js, React, AWS. NestJS is a bonus)

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• A proven track record of putting LLM/AI-powered solutions into production in the last year, features that real users rely on
• Have a practical LLM toolkit: RAG, tool use and agents, structured outputs, prompt engineering
• Know how to make AI features production-grade: eval harnesses, prompt versioning, observability, cost and latency controls, guardrails
• Be comfortable with SQL to pull what you need from the data warehouse
• Come from a maths, physics, computer science or engineering background. Not a hard requirement, but the team naturally leans this way

Package

£120,000 base. Meaningful equity. Visa sponsorship available. 4 days in their Central London office. Start ASAP.

This role is being exclusively hired through Techmunity. Apply through the advert or email me directly: reuben@techmunity.io