Lead Software Engineer

Technical Architect / Principal Engineer

London (hybrid)

90k to 105k

We’re partnering with an ambitious London‑based payments start‑up looking to hire a hands‑on Technical Architect / Principal Engineer to help shape the next generation of their platform as they scale.

This is a high‑impact opportunity for a senior engineering leader who enjoys operating across architecture, platform engineering, product delivery, and technical strategy in a fast‑moving environment.

You’ll play a key role in defining engineering standards, influencing product direction and building scalable systems capable of supporting rapid growth within a modern payments ecosystem.

The Opportunity

Joining at an exciting stage of growth, you’ll work closely with founders, product teams and engineers to design and deliver a highly scalable payments platform using modern cloud‑native technologies.

This role combines:

• technical leadership
• and mentoring responsibilities

You’ll be expected to remain close to the code while driving best practice across the wider engineering function.

Key Responsibilities

• Define and evolve platform architecture across mobile, backend and cloud infrastructure
• Lead engineering design decisions and establish scalable development standards
• Build and optimise high‑performance backend services using Node.js
• Drive mobile architecture and delivery using React Native
• Own AWS infrastructure strategy, scalability, reliability and security
• Work closely with product and leadership teams to shape technical roadmap
• Champion engineering excellence, DevOps culture, CI/CD and automation
• Explore and implement modern AI‑assisted engineering tooling and workflows

Required Experience

We’re looking for a strong technical leader with experience building scalable products within start‑up or high‑growth environments.

• Strong experience with React Native
• Strong knowledge of AWS infrastructure and cloud‑native architecture
• Experience working with PostgreSQL and scalable data design
• Proven experience operating at Technical Architect, Principal Engineer or Staff Engineer level
• Experience building scalable distributed systems and APIs
• Strong understanding of modern software engineering best practices
• Payments, fintech or regulated environment experience
• Exposure to AI‑assisted development tooling such as Claude, GitHub Copilot, Cursor or similar
• DevOps and infrastructure‑as‑code experience

What’s on Offer

• Opportunity to shape architecture from an early stage
• High ownership and autonomy
• Fast‑growing fintech business with strong leadership backing