Founding Engineer | Head of Engineering

Dex; Greater London; On-site; GBP 110,000 - 180,000; Full time

Job summary

Dex is partnering with a regulated fintech challenger to build a core banking platform in London. As the founding engineer, you’ll own the entire technical stack from concept to production, shaping architecture, security, and performance.

This is a hands-on, non-management role. You’ll set engineering culture, recruit the foundational team, and translate complex regulatory requirements into scalable financial systems that can scale with a growing business.

Qualifications

• 5–12 years of engineering experience in backend/infra.
• Proven track record building regulated financial infrastructure.
• Experience as founding or early hire at fintech or infrastructure scale.
• Expertise in distributed systems, cloud infra, data integrity, reliability and security.
• London-based or willing to relocate for in-person work.

Responsibilities

• Architect, build, and secure the core banking platform from first principles.
• Own all technical decisions across infra, backend, data, and product engineering.
• Translate regulatory requirements into scalable, compliant systems.
• Drive product from concept to production with focus on security and reliability.
• Define engineering culture and recruit the foundational team.

Skills

Backend systems

Distributed systems

Cloud infrastructure

Data integrity

Security

Founding engineer

Regulated infra

Job description

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process.

The role

This team is building a regulated financial institution from first principles. Their mission: bank and finance the companies driving Europe's defence, security, and resilience buildout. A trillion-euro market is opening up as strategic autonomy becomes a priority, and traditional banks aren't built for the startups at its core. They are backed by leading investors.

As the founding engineer, you'll own the entire technical stack from day one. This means architecting, building, and securing the core platform, taking the initial product from concept to production. This is a hands-on building role, not a management position. You'll set the engineering culture and help scale the team, working directly with the founder to translate ambitious ideas into robust, regulated systems.

The work

• Architect, build, and secure the entire core banking platform from first principles.
• Own all technical decisions: infrastructure, backend systems, data integrity, and product engineering.
• Translate complex regulatory requirements into scalable, resilient, and compliant financial systems.
• Drive the product from initial concept through to production, ensuring security and reliability.
• Define the engineering culture and recruit the foundational engineering team.

What You Bring

• 5-12 years of engineering experience, with deep expertise in backend systems, infrastructure, and production architecture.
• Proven track record building complex, highly regulated financial infrastructure (e.g., core banking, ledger systems, payments).
• Experience as a founding engineer, early hire, or senior engineer scaling a high-growth fintech or infrastructure company.
• Expertise in distributed systems, cloud infrastructure, data integrity, reliability, and security.
• London-based or willing to relocate, and committed to in-person collaboration.