Principal Java Engineer - Payments, Low-Latency Real-Time

RE Partners; Milton Keynes; Hybrid; GBP 90,000 - 130,000; Full time

Job summary

RE Partners is seeking a Principal Java Engineer to join our high-performing team in the UK. You will own the design and optimization of low-latency, high-throughput backend systems for payments, building secure RESTful APIs and scalable microservices.

In this hybrid role, you will deploy and monitor on OpenShift and AWS, integrate with MongoDB, and mentor peers while driving architectural decisions and observability enhancements across services.

Qualifications

• 10+ years in Java with focus on performance and memory optimization.
• Proficient in Mongo, Spring and microservice-based architecture.
• Proven experience with low-latency, high-throughput applications (sub-millisecond responses a plus).
• Hands-on with OpenShift and/or Kubernetes deployment.
• Strong AWS experience (ECS, EKS, Lambda, S3).
• Strong communication and bias toward action and opinionated design.

Responsibilities

• Design, develop, and optimize low-latency, high-throughput backend systems using Java.
• Build and maintain RESTful APIs and microservices powering secure payment workflows.
• Work with messaging standards and protocols used in financial transactions.
• Deploy, monitor, and scale applications in OpenShift and AWS.
• Integrate with MongoDB and other data stores for real-time data management.
• Collaborate with DevOps, Product, and QA to deliver production-grade solutions.
• Drive architectural changes and mentor peers.
• Drive performance tuning, fault tolerance, and observability improvements.

Skills

Java

Spring

Microservices

OpenShift

AWS

MongoDB

Low-latency

Tools

OpenShift

Kubernetes

MongoDB

AWS

REST APIs

Job description

RE Partners is seeking a Principal Java Engineer to join our high-performing team in the UK. You will own the design and optimization of low-latency, high-throughput backend systems for payments, building secure RESTful APIs and scalable microservices.

In this hybrid role, you will deploy and monitor on OpenShift and AWS, integrate with MongoDB, and mentor peers while driving architectural decisions and observability enhancements across services.