Lead Software Developer

Salary: £49,000 - 89,000 per year

Requirements:

• Proven experience architecting end-to-end systems and running them in production at a scale of millions of users.
• Strong systems-thinking skills, including understanding how components interact, where failures can occur, and how systems behave at increased volume.
• Strong understanding of retries, idempotency, backpressure, and message delivery edge cases.
• Strong TypeScript skills and ability to become productive in other technologies quickly.
• AI-native approach and ability to set team practices for AI-assisted planning and evaluations.
• UK right to work required.
• Bonus: experience leading a team or working in UK property or utilities.

Responsibilities:

• Design and build the platform architecture, including the relationships between households, properties, partners, and suppliers.
• Build clear order state machines and define contracts across domains, data, queues, and infrastructure.
• Design for speed and reliability, including latency budgets, observability, rehearsed rollbacks, and frequent small production changes.
• Move live systems onto a modern technology stack without disrupting service.
• Provide permissioned access for Jay and partner agents to read and act, with idempotency, audit trails, and safeguards around money.
• Enable commercial teams to change pricing through configuration rather than code deployments.
• Own outcomes end to end, clear blockers, and help establish how the engineering team works.
• Raise engineering standards and contribute to a joyful, collaborative working environment.

Technologies:

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

More:

We are building Jay, a personal AI that helps households manage moving and ongoing home services, from setting up utilities and insurance to tracking renewals and finding better deals. Our platform connects the property industry with hundreds of suppliers through a shared entity model and API, starting in the UK and with global ambitions. We are a B Corp and FCA regulated, and report a 4.9 rating on Trustpilot and Google. Our stack includes TypeScript, Python, FastAPI, Next.js, AWS, and Claude Code; we are open to changing it. The role is based in London, with a few days a week in the office, reports to the Head of AI and Engineering, and offers competitive cash compensation plus equity. We describe the hours as generally offering great work-life balance, with late nights and weekends during crunch time.

last updated 39 week of 2026