Lead Backend Engineer

Just Move In; Greater London; Hybrid; GBP 120,000 - 160,000; Full time

Job summary

Just Move In is hiring a Lead Backend Engineer to architect a global agentic-first platform for moving and home life. You will own end-to-end architecture, ensure sub-second live reads, and enable agents with secure, auditable access while driving observability and rollback readiness.

The stack includes TypeScript on the backend, Python/FastAPI for Jay, Next.js frontend, and AWS infrastructure. London-based role, hybrid with a few office days.

Qualifications

• You're a systems thinker first. How the parts interact, where failure hides, what breaks at ten times the volume.
• You've 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. Retries, idempotency, backpressure, the message that arrives twice.
• You raise everyone around you. The standard goes up on work you never touch. You are great to work with and will make work more joyful.
• You're AI-native at the frontier, and you set the practice for the team, from planning to evals.
• You're strong in TypeScript, productive in whatever a problem needs within days, and happiest thinking out loud with the team.
• You've led a team, or worked in UK property or utilities.
• You've moved house in the UK and it made you angry. We want the specific story.
• You already have ideas about how it should work. Bring them to the first call.

Responsibilities

• Architect the architecture: households, properties, partners, suppliers and how they relate.
• Ensure speed and reliability with sub-second reads and a maintainable live platform.
• Treat agents as first-class customers with secure access, idempotency, and audit trails.
• Design data contracts, queues and state machines across domains.
• Deliver changes with observability and rehearsed rollback; evolve to a modern stack.

Skills

Systems thinking

End-to-end systems

Idempotency

TypeScript

AI-native

UK experience

Tools

AWS

Next.js

Python

FastAPI

TypeScript

Job description

Architect the platform that runs home life.

We're hiring a Lead Backend Engineer to design a global, agentic-first platform for moving and home life. Fast enough for live voice. Reliable enough for agents to act on their own.

4M+ home movers a year in the UK · 28M UK households to run · $1T+ global market for home services

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.

The opportunity: OpenClaw meets Amazon, for your home.

Moving is the second most stressful thing most people do, and the admin never stops. Jay is the personal AI that takes it off your plate. It sets the household up: energy, broadband, water, council tax, insurance and so much more, then keeps it running. It tracks renewals, finds the next deal, and grows with the customer from first rental to first mortgage, with credit and higher-value financial products next. People get back their time, save money and their peace of mind.

Underneath Jay is the platform you'd architect. One side plugs into the property industry: letting agents, CRMs like Alto, deposit schemes, partners like OpenRent and IKEA UK, and the systems that already know someone is moving. The other plugs into hundreds of suppliers across every category a home needs.

In the middle, one entity model and one API turn a move into services set up, switched and paid for, Stripe-like. UK first, then the world.

Nobody has rebuilt this industry for AI. The comparison sites and incumbents still run on forms and call queues. The backend is where that changes.

What you'll own: three things, end to end.

The architecture. Households, properties, partners, suppliers and how they relate. State machines every order runs on, clear enough for an agent to act on. Contracts between domains, data, queues, infrastructure. You design it and you build it.

Speed and reliability, designed in. Live voice needs sub-second reads and a platform that doesn't need babysitting. Latency budgets per domain, observability shipped with the feature, rollback rehearsed every release, small changes to production daily. You'll move live systems onto a modern stack without dropping anything.

Agents as first-class customers. Permissioned access for Jay and partner agents to read and act, with idempotency, audit trails and a hard line around money. Config over code, so commercial teams change pricing without a deploy. How you work becomes how engineering works.

How we build: a lead owns the outcome.

Whatever stands between us and it is yours to clear. How we get there is written down, twelve principles in three parts:

• Think: Customer obsessed · AI native · Thinks big · Mission before self
• Build: Master of craft · Bias for action · Delivers outcomes · Builds out loud
• Together: True ownership · Trustworthy · Seeks and gives feedback · Inspiring to work with

Who thrives here: you should apply if

• You're a systems thinker first. How the parts interact, where failure hides, what breaks at ten times the volume.
• You've 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. Retries, idempotency, backpressure, the message that arrives twice.
• You raise everyone around you. The standard goes up on work you never touch. You are great to work with and will make work more joyful.
• You're AI-native at the frontier, and you set the practice for the team, from planning to evals.
• You're strong in TypeScript, productive in whatever a problem needs within days, and happiest thinking out loud with the team.
• You've led a team, or worked in UK property or utilities.
• You've moved house in the UK and it made you angry. We want the specific story.
• You already have ideas about how it should work. Bring them to the first call.

The team and the stack: who you'd build with.

We're a B Corp, so the values are real. We're FCA regulated, so doing things properly in a regulated industry is part of how we build. And we're obsessed with the customer, which is how we hold 4.9 on both Trustpilot and Google.

The stack: TypeScript on the backend, Python and FastAPI for Jay, Next.js up front, AWS underneath, Claude Code woven through how we build. You won't have used all of it, and you'll change some of it.

The details

• Location: London, a few days a week in the office
• Hours: Work hard, play hard. Crunch time means late nights and weekends. In general, great work-life balance.
• Reports to: Head of AI and Engineering Right to work: UK right to work required