I'm hiring a founding engineer.

Most companies at this stage hire someone to build the product. We already have one. It's live on iOS and Android, it's SOC 2 certified, and people pay for it. I'm hiring someone to take it.

We do receipt and proof automation for the self-employed.

The app finds your receipts wherever they live (email, bank feeds, camera roll, texts), sorts them, matches them against your bank transactions, and produces accountant-ready exports. The model works. Now it needs an owner.

Your first job is to take the keys. Move the platform off the agency's Azure onto ours. Take custody of production. Build the automated test suite this codebase never had, and a pipeline where a green build actually means safe to ship. After that, the roadmap is yours.

How we build matters as much as what we build. Terrapin runs as an AI native pod. Claude Code and agents do the repetitive work and hand you tested, PR ready changes. You own architecture, review, security, and the hard 20 percent. AI gives you the speed. Your tests are what stop speed from turning into breakage. We ship several times a week, break almost nothing, and hold the SOC 2 line the whole way. That should excite you, not worry you.

If you're still reading and nodding, work this sentence into your application somewhere: "Engineering is the closest thing to magic that exists in the world."

The work is genuinely full stack.

.NET and C# on Azure, PostgreSQL, real ownership of infra, security and DevOps, and polished React Native and Expo across iOS and Android. The app is the product. Testing is not someone else's job here.

What you bring

• Senior level .NET and C# backend, PostgreSQL, solid API design

• Real Azure ownership: App Services, networking, Key Vault, identity, CI/CD

• Strong React Native and Expo, with actual UI taste

• Tests written with the code, not after it

• Hands on with Claude Code and agent tooling, and doing it safely in a SOC 2 world

• Bonus: fintech or payments, Plaid, applied LLM work

Why the right person will stay.
Receipts are the wedge. What we are building is a verifiable, tamper-evident record of an economic event. Proof that banks, insurers and AI agents can consume directly. Stripe built payment rails. We are building proof rails.

You work with me every day. 18+ years in fintech and payments, two exits. You own the engineering and never carry the hard architecture, security or product calls alone.

The details.
UK or EU remote for now, with solid overlap to UK hours and some travel. Openness to relocating to the UK later is a plus, not a day one requirement. Competitive base plus real founding level equity.

One hard line. You build quality in with tests and CI/CD. We are leaving the hope it works world behind. Everything else we can talk about.

To apply, tell me about something you shipped that you are proud of, and one thing you broke and how you made sure it never happened again.