Founding Product Engineer

Founding AI Product Engineer (Python, FastAPI, React)

Salary up to £150k + Equity

London Based

Most accounting firms are bolting AI onto old workflows for marginal gains. We’re doing something different: building an end-to-end agentic accounting firm where AI agents do the actual work, reconciliation, bookkeeping, reporting and humans only step in where judgment really matters, like signing off the final accounts.

Already inboarded 60+ customers across the UK and Denmark, growing 40% month-on-month, and just closed a $5M seed round led by a tier-1 VC.

Now looking for the next founding engineers #4 or #5 to help go from “promising” to “category-defining.”

What you’ll actually be doing:

You’ll be building the AI accountant and platform for the human accountants use to review its work. You’ll sit right next to the people using what you build, automate their workflows piece by piece, and keep pushing the system up a level of abstraction.

Full ownership: scoping → prototyping → shipping → monitoring → iterating.

Recent ships from the team: autonomous receipt collection, end-to-end reconciliation, a new accounting software integration. What ships next month is decided by what real customers need most, not a roadmap built in a vacuum.

Your first 90 days:

📅 Week 1 — ship your first feature

📅 Month 1 — track adoption, iterate, make sure it’s actually saving people time

📅 Quarter 1 — own a meaningful chunk of the platform

The stack: Python/FastAPI/Postgres/Redis on the backend, React/Vite/Tailwind on the front, plus serious agent-building with OpenAI and Anthropic models.

You’re a fit if you’re:

✅ A true generalist and 0→1 builder

✅ Genuinely excited about where AI agents are headed (you’ve built with the latest tools and have strong opinions on them)

If early builder roles, where your get full ownership and backing appeal to you, get in touch, as this is an already profitable start-up, with huge scope to scale.