Founding Engineer: Build & Scale FinTech Core Platform

Dex; Greater London; On-site; GBP 140,000 - 200,000; Full time

Job summary

Dex is partnering with a regulated fintech startup to build a core banking platform from first principles. As the founding engineer, you will architect, build, and secure the entire stack, taking the initial product from concept to production.

This hands-on role involves setting engineering culture and collaborating directly with the founder to translate ambitious ideas into robust, regulated systems. You will shape the team, recruit the initial engineering roster, and work with London-based

Qualifications

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

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 regulatory requirements into scalable, 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

Security

Founding engineer

Regulatory compliance

Job description

Dex is partnering with a regulated fintech startup to build a core banking platform from first principles. As the founding engineer, you will architect, build, and secure the entire stack, taking the initial product from concept to production.

This hands-on role involves setting engineering culture and collaborating directly with the founder to translate ambitious ideas into robust, regulated systems. You will shape the team, recruit the initial engineering roster, and work with London-based