Senior Backend Engineer

Senior Backend Engineer | London | AI x 0→1 Product | Python | Competitive Salary + Equity

We’re working with a $9M-backed AI company building a new product that helps people manage their travel, dining, experiences and other personal requests through AI. Early stage so you’ll be building the product from scratch, working directly with the CTO and founders.

You’ll be working mainly in Python, building backend services, APIs, data pipelines and AI features, and taking what you build into production.

No legacy systems, no internal CRM and no endless ticket queue. You’ll have real ownership over what gets built.

What you will be doing

• Architect and build the backend from the ground up you'll have a genuine say in how the system is designed
• Take ideas from 0→1, through architecture, implementation, deployment and iteration
• Build high-performance APIs, background workers, data pipelines and third-party integrations
• Design and ship AI agent workflows, including LLM orchestration, tool calling and retrieval
• Solve problems around latency, reliability, observability, cost and model performance
• Make the difficult calls around architecture, infrastructure and technical trade-offs
• Work directly with the CTO and founders no six layers between you and the decision
• Ship to real users, learn from what breaks, and improve it

What I'm Looking For

• Excellent software engineering fundamentals CS fundamentals actually matter here
• Strong production experience with Python
• Strong backend/API engineering experience
• Experience building and shipping 0→1 products or significant greenfield systems
• Strong understanding of distributed systems, databases, concurrency and asynchronous processing
• Hands-on experience with LLMs, AI agents, RAG, embeddings or model-driven applications
• Someone who can look at an ambiguous problem and work out the architecture rather than waiting for someone else to define it
• A track record of shipping GitHub, products, side projects, startups, whatever proves you build

Tech Stack

• FastAPI / Django
• PostgreSQL
• AWS
• Redis / Celery / Kafka
• Vector databases
• Agent orchestration / tool calling
• RAG / retrieval systems
• LLM evaluation and observability
• AI-native products
• High-growth startups
• Strong open-source projects

Top university / Computer Science background is highly valued, particularly from places such as Imperial, Cambridge, Oxford, UCL, Edinburgh or Warwick but I'm much more interested in what you've actually built than a university name on a CV.

Why this one is different You won't be joining a huge engineering organization and owning 3% of a service nobody understands. You'll be one of the engineers actually building the thing. You'll have direct access to the people making the decisions, meaningful equity, serious technical ownership and the opportunity to put your fingerprints on the architecture before it becomes difficult to change.

If you're the type of engineer who sees 0→1, greenfield, AI agents and “figure it out” and thinks that's exactly what I want to be doing! I'd like to hear from you

Apply with your CV.