Lead Software Developer

Salary: £49,000 - 89,000 per year

Requirements

• We are looking for a truly world-class engineer who has seen what great looks like and can take ownership to build the foundations for a global agentic marketplace.
• You are a systems thinker first, understanding how the parts interact, where failure hides, and what breaks at ten times the volume.
• You have architected real systems end to end more than once, and run them in production at the scale of millions of users.
• You take the edges seriously, including retries, idempotency, backpressure, and messages that arrive twice.
• You raise everyone around you and are great to work with.
• You are AI-native at the frontier and set the practice for the team, from planning to evals.
• You are strong in TypeScript and productive in whatever a problem needs within days.
• You are happiest thinking out loud with the team.
• You have led a team, or worked in UK property or utilities, which is a bonus.
• You already have ideas about how it should work and can bring them to the first call, which is a bonus.
• UK right to work required.

Responsibilities

• Architect the platform that runs home life.
• Design a global, agentic-first platform for moving and home life.
• Own the architecture end to end, including households, properties, partners, suppliers, and how they relate.
• Design state machines every order runs on so an agent can act on them.
• Define contracts between domains, data, queues, and infrastructure.
• Build the architecture yourself.
• Design speed and reliability into the platform from the start.
• Deliver sub-second reads for live voice use cases.
• Ship observability with the feature.
• Rehearse rollback every release.
• Move live systems onto a modern stack without dropping anything.
• Make agents first-class customers with permissioned access for Jay and partner agents to read and act.
• Implement idempotency, audit trails, and strong controls around money.
• Enable config over code so commercial teams can change pricing without a deploy.
• Clear whatever stands between the team and the outcome.
• Set the working model for engineering through the way you work.

Technologies

• AI
• API
• AWS
• Architect
• Backend
• Claude Code
• FastAPI
• Python
• TypeScript
• Cloud

More

We are building Jay, the personal AI that takes home-moving and household admin off peoples plates by setting up and managing energy, broadband, water, council tax, insurance, renewals, and more. We are UK first, then expanding globally, and we sit between the property industry and hundreds of suppliers to turn a move into services that are set up, switched, and paid for through one entity model and one API. We are a B Corp and FCA regulated, with customer obsession reflected in our 4.9 Trustpilot and Google ratings. Our stack includes TypeScript on the backend, Python and FastAPI for Jay, Next.js on the front end, AWS underneath, and Claude Code woven through how we build. The role is London-based with a few days a week in the office, offers cash plus equity, reports to the Head of AI and Engineering, and requires UK right to work.

last updated 38 week of 2026

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