Senior Java Software Engineer

RE Partners; New York (NY); Hybrid; USD 140,000 - 170,000; Full time

Job summary

RE Partners in New York is seeking a Senior Java Engineer to join a small, elite team building a high-impact payments platform used by a top-tier institution. You’ll design, implement, and optimize low-latency services that process millions of transactions per second.

You’ll own services end-to-end, tackle concurrency challenges, and drive performance improvements in a cloud-native stack (Java, Spring Boot, Kafka, Kubernetes).

Qualifications

• 8+ years of hands-on Java development experience.
• Strong experience with multithreading and concurrency in production.
• Good understanding of distributed systems and cloud-native architectures.
• US 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 development

multithreading

distributed systems

cloud-native architectures

US work authorisation

Tools

Kafka

Job description

Job Title: Senior Java Engineer – High-Volume Payments Platform

Employment Type: Full-time, Permanent (W2)

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
• US 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
• US work authorisation is required – we are unable to provide visa sponsorship for this role