Full Stack Engineer

limitless; Greater London; Hybrid; GBP 90,000 - 150,000; Full time

Benefits offered by this job

Equity stake

London office

Job summary

limitless is hiring founding-level Full-Stack Engineers to own the entire stack, from Python/FastAPI backend to the Next.js/TypeScript frontend. Build AI agents for tenant engagement, landlord outreach, compliance and maintenance, and orchestrate LLM-powered systems.

You'll lead architecture decisions, ship production-grade integrations, and own the system from day one in a fast-paced, equity-rich environment in London.

Qualifications

• 3+ years of Python with strong FastAPI experience, async APIs, event-driven services, and solid fundamentals (DB design, queuing, CI/CD).
• 2+ years building and shipping AI agents or LLM-powered systems in production with end-to-end orchestration.
• Strong RAG experience with vector databases (Pinecone, pgvector or similar).
• Proficient in TypeScript/React/Next.js in production, not side projects.
• Experience with Postgres, Redis and cloud environments (GCP/AWS) with observability and debugging tools (Datadog, Sentry, LangSmith).
• Led a system from 0 to 1, preferably at an early-stage startup or solo product effort.
• Ability to discuss product and code ownership; seeking a founding seat with equity.

Responsibilities

• Own the Python/FastAPI backend that orchestrates AI agents, real-time voice, LLM orchestration, RAG pipelines and event-driven architecture.
• Handle API integrations with CRMs and property platforms, data modeling, webhooks, and production-grade plumbing.
• Contribute to the Next.js/TypeScript frontend used by operators and customers.
• Represent architecture decisions, moving fast from concept to production, not waiting for others.

Skills

Python

FastAPI

AI agents

LLM orchestration

TypeScript

React

Next.js

Postgres

Redis

CI/CD

Tools

Datadog

Sentry

LangSmith

Pinecone

pgvector

LiveKit

Twilio

AWS

GCP

Job description

Property still runs on scribbles, spreadsheets and "sorry, we missed your call." My client is fixing that - building AI workers that handle tenant engagement, landlord outreach, compliance and maintenance autonomously, replacing decades-old agency workflows.

$5.5m+ raised from top-tier VCs, already live with agencies across the UK and gaining traction in the US.

Now they need founding-level Full-Stack Engineers to own the whole stack, not a slice of it.

You'll build the Python/FastAPI backend that orchestrates the AI agents - telephony and real-time voice, LLM orchestration, RAG pipelines, and the event-driven architecture tying it all together. Just as much of this is traditional backend engineering too: API integrations with CRMs and property platforms, data modelling, webhooks, the plumbing that makes the AI actually work in production. You'll also touch the Next.js/TypeScript frontend the operators and customers use directly.

Concept to production in days, not sprints. You're making the architecture calls, not waiting for someone else to.

There's no legacy to inherit here. You're setting the standard everyone after you works to.

You'll love this if you:

• Have 3+ years of Python with genuinely strong FastAPI experience - async APIs, event-driven services, and solid fundamentals underneath (database design, queuing, CI/CD), not just surface familiarity
• Have 2+ years building and shipping AI agents or LLM-powered systems in production - real end-to-end orchestration (LangGraph or similar), not just having called an LLM API
• Have strong, evidenced RAG experience - structuring unstructured data, hands-on with vector databases (Pinecone, pgvector or similar)
• Can go equally deep on TypeScript/React/Next.js in production, not side projects
• Know your way around Postgres, Redis, and GCP or AWS in a live environment, with real observability and debugging chops (Datadog, Sentry, LangSmith or similar)
• Have genuinely taken something from 0 to 1 - built and owned an entire system from scratch, ideally at an early-stage startup or solo on your own product
• Are a fast, sharp thinker who can talk product as naturally as code - this is a founding seat, and we're looking for outsized impact, not just competent delivery
• Want a founding seat and the equity that comes with it, not a job spec someone else already wrote

Nice to have: voice AI / real-time communication experience (LiveKit, Twilio, WebRTC, STT/TTS)

In-office five days a week in London.

Heads up on process: this one moves fast but goes deep - expect real technical depth-checking on whatever you list, plus genuine curiosity about how you think about ownership and product, not just code.

Fast-paced, high-ownership, high-intensity, high reward!

If you want to build the engineering function from scratch at a company about to change how an entire industry works, this is the one.