Founding Engineer (£100-130k + 0.8% Equity) at Spinal

Job Title: Founding Engineer

Salary: £100-130k + 0.6-0.8% Equity

Company Description: Spinal - VC-backed AI automation for modern finance teams

Location: London, UK

Job Description

As the third founding engineer at this London Bridge-based startup, you will build agentic AI systems that automate complex accounts receivable workflows. You'll transform unstructured contracts into live invoicing and revenue recognition engines, working directly with the founders to replace manual spreadsheets with deterministic, AI-driven financial infrastructure in a fast paced, in office environment.

Why this role is remarkable

• Join as employee with a true founding equity stake and direct influence over the architectural evolution of the core product.
• Build at the cutting edge of agentic AI using LangGraph and Temporal to solve high stakes, multi billion dollar problems in finance.
• Work in a high intensity, collaborative environment in London Bridge with a team that prioritizes shipping fast and weekly demo sessions.

What you will do

• Design and deploy agentic AI systems that extract complex billing terms from unstructured legal documents and PDFs.
• Architect and maintain robust backend services using Python, Pydantic, and Postgres to power end to end collections and revenue recognition.
• Collaborate directly with the CTO to translate customer needs into production ready features that eliminate manual finance workflows.

The ideal candidate

• 3-5 years of experience as a Python backend engineer with a proven track record of shipping complex systems from zero to one.
• Hands on expertise with agentic AI frameworks such as LangGraph or LangChain, specifically for processing unstructured data into structured outputs.
• A founding mindset demonstrated through previous early stage startup experience, academic distinction, or a high performance background in competitive fields.

Next steps

1. Visit our website.
2. Click Talk to Jack.
3. Talk to Jack so he can understand your experience and ambitions.
4. Jack will make sure Jill (the AI agent working for the company) considers you for this role.
5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.
6. If not, Jack will find you excellent alternatives.