Backend Engineer - AI PropTech Startup

London, Hybrid (weekly office attendance preferred, min. 1-2 days)

Level: Senior

We're working with an PropTech start-up to find two Senior Backend Engineers to join their team as they build out a genuinely green-field AI product from scratch.

They're launching two parallel AI workstreams:

• Augmentation - AI assisting operations teams on complex, high-risk tasks (finance, invoicing)
• Automation - fully automating high-volume, low-risk repetitive workflows

The core mechanic is benchmarking LLMs to perform automated steps in workflows. For engineers frustrated by bolt-on AI at their current employer, this is the opportunity to build it properly from day one.

The Role

The successful candidate will own and develop the core applications powering the business - primarily CRM and finance services - for both internal and external users. They'll work in one of two small engineering teams (3-4 engineers), hands-on from day one, shipping fast using agentic development workflows.

This isn't a role for someone used to delegating in a large org. The right person will own services end-to‑end, in a fast‑growth environment where priorities shift and velocity matters.

You'll work in one of two small engineering teams (3-4 engineers), hands-on from day one, shipping fast using agentic development workflows.

This is not a role for someone used to delegating in a large org. You'll own services end-to‑end, in a fast‑growth environment where priorities shift and velocity matters.

What They're Looking For

• Fast-growth startup / scale-up experience. Candidates should have worked at a Stealth Start-up/Series A/B startup through a period of rapid scaling, and be comfortable with ambiguity, shifting priorities, and shipping under pressure without over‑engineering. Early or founding engineer experience, ownership of significant surface area, and demonstrable velocity are all a strong fit.
• Strong, current production Python with FastAPI - this is a hard requirement. Experience with API design, async Python, and SQL/ORM is a plus.
• Genuine, current use of agentic development workflows. Candidates should actively use AI coding agents (e.g. Claude Code, Cursor) as a core part of how they work, and think about optimising their own and their team's development workflow - tooling, automation, spec‑driven development.
• Ownership of quality. Writes and maintains their own tests, and is comfortable in a "you build it, you run it" culture.

What They're NOT Looking For

• No FastAPI / weak Python
• Unable to travel to the office 1-2 days a week
• Purely frontend focus with no backend service ownership
• No evidence of scale‑up or agentic development experience
• Ultra‑high performers from AI‑first rocketships (salary expectations typically exceed range)

Ideal Background

Strong candidates typically come from lean, fast‑scaling product companies with a genuine engineering culture (rather than large corporates, agencies/consultancies, or businesses without a strong tech function), bringing hands‑on, current experience shipping production Python/FastAPI services alongside real agentic‑AI‑assisted development practice.

If you're frustrated by bolt‑on AI at your current employer, this is the opportunity to build it properly from day one.