Founding Engineer: Architect & Scale Core Banking Platform

Dex; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

Dex partners with a regulated fintech startup to recruit a founding engineer who will own the entire technical stack from day one, architecting, building, and securing the core platform. This is a hands-on building role, not a management position, with the founder and early team setting the engineering culture.

You will translate ambitious regulatory requirements into robust, scalable financial systems, drive productization from concept to production, and help scale the team while ensuring

Qualifications

• 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.

Responsibilities

• 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.

Skills

Backend systems

Distributed systems

Cloud infrastructure

Data integrity

Production architecture

Security

Founding engineer

Regulated financial infra

London-based/relocation

Job description

Dex partners with a regulated fintech startup to recruit a founding engineer who will own the entire technical stack from day one, architecting, building, and securing the core platform. This is a hands-on building role, not a management position, with the founder and early team setting the engineering culture.

You will translate ambitious regulatory requirements into robust, scalable financial systems, drive productization from concept to production, and help scale the team while ensuring