End-to-End AI Full-Stack Engineer – Real Estate (London)

Company: Letty
Apply for the End-to-End AI Full-Stack Engineer – Real Estate (London)
Location: London
Job Description:

Hoxton, London. In-office 5 days a week, on-site.

PLEASE DO NOT APPLY IF YOU ARE NOT IN THE UK

This will be the hardest job you’ve ever had.

We operate with the intensity and speed of an SF YC-stage startup, but in London. Shipped features, not endless planning. We need an engineer who can own technical systems end-to-end and thrive in a fast-paced, high-stakes, five/six-day-a-week environment.

What we’re building

Our starting point is selling to real estate agencies, where we’re replacing manual workflows with AI employees that handle tenant engagement, landlord outreach, compliance, and maintenance autonomously.

Property is one of the most important parts of people’s lives, and the experience of buying, selling or renting one is still terrible. The industry is fragmented, compliance-heavy, and deeply inefficient. It runs on spreadsheets, missed calls, and manual processes that haven’t changed in 30 years.

Nobody has built the definitive AI agent layer for real estate yet. That’s what we’re doing.

  • Backed by Entrepreneurs First and top-tier VCs
  • Live with agencies across the UK with early US traction
  • Building AI agents that don’t just assist. They do the work.
  • Based in Hoxton, London. In-office 5/6 days a week.

The Role

As a Full-Stack Engineer, you’ll:

Own backend, frontend, infrastructure, and deployment. Full-stack ownership.

  • Make architectural decisions that shape our product
  • Ship features from concept to production in days, not weeks/months
  • Work closely with the founding team on strategic technical direction
  • Mentor future engineers as we scale (you’ll be early enough to shape culture)
  • Debug production issues at 2am without hesitation, then ship the fix by morning

You’ll touch every layer of what makes our AI agents actually useful in production:

  • The Python / FastAPI backend that orchestrates our agents
  • LLM orchestration and RAG pipelines
  • Telephony and voice infrastructure (real-time calls, STT/TTS)
  • Messaging integrations (WhatsApp, SMS, email)
  • API integrations with property management and CRM systems
  • A Next.js / TypeScript frontend that operators and customers actually use

Required Skills

Mandatory (non-negotiable)

  • Python. Backend systems, scripting, data processing.
  • FastAPI. Async APIs and event-driven services.
  • Next.js / React. Production apps real users touch.

This is not a feature-builder role. You’re creating entire systems, making tradeoffs, and owning their outcome end-to-end.

Highly desired

  • Track record building products from 0 to 1 or scaling at an early-stage startup
  • Hands-on with LLMs in production (orchestration frameworks, vector databases, evals)
  • System design and architecture experience
  • Ability to read unfamiliar code and understand it quickly

Nice to have

  • 1+ years at a top-tier tech company
  • Desire to found in the future

We value taste, speed, and a maker’s mindset over credentials.

How we work

This is not a 9-to-5 role. We operate with YC startup culture in London.

  • 12-hour days are standard. 10am to 10pm or similar flexibility.
  • Five-Six-day working weeks
  • 5 days – In-office in Hoxton
  • High-intensity environment. Fast decisions, high stakes, rapid iteration.
  • Fast feedback loops. Ideas to code to production in days.
  • High ownership, high autonomy. You make calls, not committees.

We are rebuilding a $1T+ industry and we don’t think that happens on a 9-to-5.

If you’re optimising for work-life balance, predictable hours, or a slow pace, this isn’t for you. We need people energised by intensity, not drained by it.

This role isn’t for you if

  • You want a predictable 9-to-5
  • You optimise for work-life balance over output
  • Six days a week in the office sounds exhausting rather than energising
  • You want to feature-build instead of system-build

What we offer

  • Front-row seat to building the AI agent layer for a $1T+ industry
  • A team obsessed with winning. Small, fast, building something that matters.
  • Uber home when you’re working late
  • DoorDash dinners in the office
  • Brand new MacBook

But the real offer is ownership. You own the system. You make the calls. No committees, no waiting for permission.

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Posted: May 27th, 2026