Lead Software Engineer

About the job

Lead Software Engineer

Stealth AI Fintech Startup | London | Hybrid (3 days on-site)

We're hiring on behalf of a venture‑backed fintech building an AI‑driven platform transforming how investors analyse and manage alternative assets such as private equity and private credit.

The MVP is built. Funding is secured from experienced fintech founders and senior figures in financial services. Now the focus is scaling the product properly, with strong architecture, clean engineering standards, and production‑grade systems.

They’re looking for a Lead Engineer who wants to be deeply hands‑on and shape the technical foundation from within the codebase.

This is not a management‑heavy position. You won’t be spending your days in planning meetings or overseeing layers of engineers.

You’ll be coding daily.

You’ll design and evolve the architecture of an AI‑native SaaS platform that automates due diligence and investment workflows in a legacy financial industry.

You’ll set the technical standard by doing the work: writing clean systems, making pragmatic architectural decisions, and solving hard problems alongside the team.

You’ll lead the architecture of an AI‑driven investment intelligence platform while staying deeply hands‑on across the entire stack, from frontend UX to backend services, AI integrations, and core infrastructure. Working closely with the CTO, data scientists, and product leadership, you’ll help shape both the technical direction and the product itself.

You’ll build and mentor a small, elite engineering team, setting a high technical bar through example while driving strategy around scalability, security, and reliability. Along the way, you’ll explore and integrate emerging AI frameworks, tools, and blockchain technologies to keep the platform at the cutting edge.

• 5+ years professional software engineering experience
• 2+ years operating at senior/lead level
• Strong ownership mindset, you don’t wait to be told
• Comfortable building in ambiguity
• Node.js, React & Type Script
• Python for AI automation and workflows
• Microservices & distributed systems
• AI/LLM frameworks (Lang Chain, OpenAI API, Vertex, LiteLLM)
• GCP & Dev Ops best practices
• Postgre
  
  SQL and relational modelling
• Event‑driven systems (Kafka, Pub/Sub) + MongoDB
• Experience shipping production SaaS platforms

• RAG, autonomous agents, MCP
• Exposure to blockchain or tokenisation frameworks
• Security, cryptography or distributed systems knowledge
• Fintech or asset management experience

• Build a technically ambitious AI product in fintech
• Stay fully hands‑on while influencing core architecture
• Work alongside an experienced CTO and high‑calibre team
• Real ownership, your technical decisions directly shape the platform
• High‑trust, low‑bureaucracy environment where output matters