Full Stack Engineer (£70k-£110k + Equity) at Y Combinator-backed AI fintech startup

Company: Jack & Jill
Apply for the Full Stack Engineer (£70k-£110k + Equity) at Y Combinator-backed AI fintech startup
Location: London
Job Description:

Job Title

Full Stack Engineer (AI Agents)

Salary

£70k-£110k + Equity

Company Description

Y Combinator-backed fintech infrastructure startup automating AML operations

Job Description

Join a high-growth London team building autonomous AI agents that handle complex KYC/AML workflows for global financial institutions. You will scale a platform already serving publicly listed banks across the US, EU, and Japan, moving from product-market fit to rapid expansion while owning core infrastructure and critical API systems.

Location

London, UK

Why this role is remarkable

  • Work directly with the founding team in a post-seed environment with significant runway and real traction with major global financial institutions.
  • Take end-to-end ownership of product releases that fight financial crime, automating tedious manual tasks for compliance teams worldwide.
  • Access a highly technical culture with deep fintech expertise and a serverless-first approach to building scalable AI infrastructure.

What You Will Do

  • Architect and build core AI agent infrastructure and API systems using TypeScript/JavaScript on AWS serverless environments.
  • Design and implement critical integrations with legacy KYC/AML platforms relied upon by international banking partners.
  • Collaborate directly with the CEO and CTO to translate customer feedback into rapid product deployments and architectural improvements.

The ideal candidate

  • 1-5 years of experience building production systems, specifically demonstrating signs of excellence via top-tier universities or elite tech firms like Google or Stripe.
  • Strong proficiency in JavaScript/TypeScript and serverless architecture (AWS) with a focus on high-quality backend engineering and CI/CD practices.
  • A proven “builder mindset” evidenced by founding a company, launching side projects with users, or scaling early-stage VC-backed startups.

#J-18808-Ljbffr…

Posted: June 15th, 2026