Most Engineering roles right now involve slapping a basic wrapper around a generic API and calling it a day. This isn't one of those..

We are partnering with an exceptionally high-performing, newly funded (£3M pre-seed) FinTech start-up that is building actual agentic AI systems. Instead of trying to force users onto a shiny new platform they don't want, our client embeds custom AI sub-agents natively right where financial advisors and accountants already live: Microsoft Excel. By automating tedious, spreadsheet-heavy workflows and complex compliance calculations, they are saving global professional services firms hundreds of manual hours.

They already have massive commercial traction, including a major agreement with a global corporate services giant and active deployments across Big 4 firms (KPMG, EY, Deloitte). To keep up with this demand, they are expanding their tight-knit engineering team from 3 to 5.

The Mindset: What You'll Actually Do

This is a product-first environment with zero corporate red tape. The philosophy here is simple: what you build, you own. You’ll spend your time shipping real features from the database layer right up to the React components.

• Long-Term Ownership: This isn't an agency setup where you ship code and walk away. You’ll maintain, refactor, and mature what you build over time based on real user feedback.
• Work Alongside AI Engineers: You don't need a background in Machine Learning, but you do need to be deeply curious about it. You’ll be building the critical scaffolding, APIs, and UIs that expose and route these complex agentic systems.
• Psychological Safety: They move in fast, 1-week sprint cycles. The motto is "make mistakes fast and fix them fast." They have excellent observability systems in place, so when something breaks, the team rallies together to solve it and learn from it.

What We’re Looking For

• The Sweet Spot: Experience within a product-focused environment.
• Core Tech: Proficient with TypeScript, Node.js, and React. Some cloud exposure (AWS/Serverless) is ideal, but you don't need to be an infrastructure wizard.
• Engineering Discipline: A solid appreciation for TDD (Test-Driven Development), whether from your professional work or personal projects.
• Longevity & Curiosity: We value engineers who have stuck around to see the long-term impact of their code rather than jumping frequently between short-term contracts. An active side project or a genuine passion for building things outside of work is a massive bonus.

The Environment & Perks

Based in a fantastic, highly social office space in London, the team thrives on in-person collaboration and mentorship.

• The Office: Complete with a dog-friendly policy, an incredible rooftop for socialising, and an on-site gym located right downstairs (with membership covered).
• The Onboarding: Week 1 is a soft onboarding to get familiar with the stack, followed by 3 weeks of structured pair programming on shared tasks before you start picking up features independently.

**No sponsorship can be provided for this role.

If you are a curious, product-minded engineer who wants to be at the front line of how real AI products get built, let's have a chat 😊