Senior Java Software Engineer

RE Partners; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Job summary

RE Partners is seeking a Senior Java Engineer to join a small, elite team delivering a high-impact payments platform for a top-tier investment bank. You will design and optimise low-latency microservices, build with Java 21, Spring Boot, Kafka, and Kubernetes, and own services from design to production support.

The role requires 8+ years of hands-on Java experience, strong concurrency skills, and a good understanding of distributed systems.

Qualifications

• 8+ years of hands-on Java development experience.
• Strong experience with multithreading and concurrency in production.
• Experience with Kafka (or similar messaging systems).
• Good understanding of distributed systems and cloud-native architectures.
• UK work authorisation (no visa sponsorship available).

Responsibilities

• Design, build, and optimise low-latency, high-throughput microservices using Java 21, Spring Boot, Kafka, and Kubernetes.
• Own services end-to-end – from architecture and implementation to deployment and production support.
• Work on concurrency, multithreading, and performance tuning – solving real production problems.
• Collaborate with a small, senior team – no hand-holding, real ownership.
• Drive code quality, engineering standards, and best practices across the organisation.

Skills

Java

Multithreading

Distributed systems

Spring Boot

Kafka

Kubernetes

AWS

Tools

Kafka

Kubernetes

AWS

Job description

The Opportunity

We are looking for a Senior Java Engineer to join a small, elite team working on a high-impact payments platform for a top-tier investment bank. This is not a generic CRUD role. You'll be building and optimising systems that process millions of transactions per second – low-latency, high-throughput, mission-critical. The team is senior, empowered, and takes full ownership of services from design to production support. If you're a hands-on Java engineer who enjoys solving complex performance problems, debugging threading issues, and working with modern tech, this could be the right move for you.

What You'll Be Doing

• Design, build, and optimise low-latency, high-throughput microservices using Java 21, Spring Boot, Kafka, and Kubernetes
• Own services end-to-end – from architecture and implementation to deployment and production support
• Work on concurrency, multithreading, and performance tuning – solving real production problems
• Collaborate with a small, senior team – no hand-holding, real ownership
• Drive code quality, engineering standards, and best practices across a wider organisation

What We're Looking For

Must-Have:

• 8+ years of hands-on Java development experience
• Strong experience with multithreading and concurrency in production
• Experience with Kafka (or similar messaging systems)
• Good understanding of distributed systems and cloud-native architectures
• UK work authorisation (no visa sponsorship available)

Nice to Have

• Experience in banking, financial services, or payments
• Experience with Kubernetes and AWS
• Knowledge of FIX protocol or electronic trading systems
• Experience with performance tuning and optimisation

Why Join?

• Meaningful Work: You'll be building systems that power global payments – your code will have real impact
• Modern Tech Stack: Java 21, virtual threads, Kafka, Kubernetes, AWS – no legacy maintenance
• Senior Team: Work alongside engineers with elite banking and tech backgrounds
• Real Ownership: You'll own services from design to production – not just tickets
• Long-Term Stability: This is a permanent role – we've had people on this project for over 3 years
• Hybrid Flexibility: 2-3 days per week in Canary Wharf, rest remote
• UK work authorisation is required – we are unable to provide visa sponsorship for this role