Back End Developer

Morr0; Greater London; On-site; GBP 110,000 - 170,000; Full time

Job summary

Morr0 is seeking a Senior - Principal Backend Engineer for London or Amsterdam to build core fintech backend systems and scale the platform for cross-border operations.

You will shape architecture, own design decisions from the outset, and collaborate with experienced engineers to deliver reliable, scalable infrastructure.

Qualifications

• Strong backend engineering experience, ideally in fintech, payments or similarly complex systems.
• Fluency in a JVM language, preferably Kotlin.
• Sound judgement around architecture, data modelling and distributed systems.
• Someone comfortable taking a loosely defined problem and owning it through to delivery.

Responsibilities

• Build core backend systems across payments, multi-currency ledgers, tax engines and workflow automation from scratch.
• Take ownership from early design decisions through to production.
• Influence architecture and work directly with founders to shape platform development.
• Deliver reliable, scalable solutions with a strong focus on correctness and performance.

Skills

Backend engineering

Fintech

Kotlin

Distributed systems

Tools

JVM

Kotlin

Job description

Senior - Principal Backend Engineer | FinTech | London or Amsterdam

Join an early-stage Fintech building AI-powered infrastructure to simplify how businesses operate across borders.

International growth still comes with a lot of disconnected financial systems, manual processes and operational complexity. This team is bringing those pieces together into a platform that makes it easier for businesses to enter and operate in new markets.

The role

You’ll build core backend systems across payments, multi-currency ledgers, tax engines and workflow automation from scratch, taking ownership from early design decisions through to production.

The engineering team is small, so you’ll have significant influence over the architecture, work directly with the founders and help decide how the platform develops as the business grows.

Expect technically demanding work where correctness, reliability and scale matter, alongside the freedom to make decisions and see them through.

The team

You’ll join experienced engineers and operators who have helped build the likes of Revolut, Airwallex, Adyen & Yandex. They bring deep experience in payments and financial infrastructure, with strong funding behind them and plenty still to build.

• Strong backend engineering experience, ideally in fintech, payments or similarly complex systems.
• Fluency in a JVM language, preferably Kotlin.
• Sound judgement around architecture, data modelling and distributed systems.
• Someone comfortable taking a loosely defined problem and owning it through to delivery.