Senior Java Engineer - Fintech

X4 Technology; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Training & progression

Wellbeing initiatives

Lifestyle benefits

Job summary

X4 Technology is seeking a Senior Software Engineer to join a market‑leading fintech platform in London. You will work on real‑time payment infrastructure, integrating scalable, resilient Java applications within a collaborative product engineering team.

You’ll contribute to architectural decisions, build high‑quality reusable code, and help shape future capabilities while embracing CI/CD, Agile delivery, and cutting‑edge tech such as Kafka, Spring, and distributed systems.

Qualifications

• Proficiency in Java 11+ and Spring.

Responsibilities

• Develop and maintain scalable, resilient Java services in a FinTech platform.
• Collaborate with product engineering to drive architectural decisions and best practices.

Skills

Java 11+

Spring framework

Kafka

Distributed systems

CI/CD

Agile delivery

High availability

FinTech/payments experience

Tools

AKKA

Docker

Kubernetes

MongoDB

Angular

Ansible

Job description

Senior Software Engineer | Java | FinTech | Hybrid ( 2 Days per week)

I'm currently partnering with an innovative fintech that's helping some of the world's leading financial institutions modernise their payment infrastructure through cutting‑edge, real‑time payment technology.

This is an opportunity to join a highly collaborative product engineering team, integrating a market‑leading platform that processes high‑volume, mission‑critical transactions. You'll play a key role in integrating and building scalable, resilient applications while contributing to architectural decisions and engineering best practices.

What you'll be working with:

• Spring Framework
• Reactive Programming

You'll be involved in writing high-quality, reusable code, solving complex engineering challenges, and helping to shape the future of a platform trusted by major financial organisations.

We're looking for engineers with experience in:

• Java 11+ and Spring
• Kafka
• Fintech, Banking or Payments experience
• Building asynchronous, event‑driven or distributed systems
• CI/CD and Agile delivery
• Designing scalable, high‑availability applications
• Experience with AKKA, Docker, Kubernetes, MongoDB, Angular or Ansible would be advantageous but isn't essential.

What's on offer?

• Ongoing training and defined career progression
• Wellbeing initiatives and additional lifestyle benefits