Principal Java Developer

About this role

Principal Java Developer We are seeking an experienced and opinionated Principal Java Engineer to join our high-performing engineering team, working on low latency, high-throughput systems in the payments processing domain. This hybrid role is based in the UK and offers the opportunity to build scalable, real-time services using modern technologies.If you’re passionate about performance, have strong Core Java and SpringBoot expertise, and thrive in a collaborative yet opinionated engineering culture, we want to hear from you.

Key Responsibilities: Design, develop, and optimize low-latency, high-throughput backend systems using Java. Build and maintain RESTful APIs and microservices that power secure payment workflows. Work with messaging standards and protocols commonly used in financial transactions. Deploy, monitor, and scale applications in Red Hat OpenShift and AWS cloud environments. Integrate with MongoDB and other NoSQL/SQL datastores for real-time data management.

Collaborate with DevOps, Product, and QA teams to ensure production-grade solutions. Drive architectural changes, advocate for best practices, and provide mentorship to peers. Drive performance tuning, fault tolerance, and observability improvements across services. Required Skills & Experience: 10+ years of experience in Java development with a focus on performance and memory optimization. Proficient in Mongo, Spring and microservice-based architecture.

Proven experience with low-latency, high-throughput applications (sub-millisecond response times a plus). Hands-on experience deploying applications on Red Hat OpenShift and/or Kubernetes. Strong cloud experience with AWS services such as ECS, EKS, Lambda, S3, etc. Strong communication skills and a bias toward action and opinionated design decisions. Nice to Have: Familiarity with messaging systems (Kafka, RabbitMQ, etc.) Prior experience in Payments Processing, financial services, or banking systems.

Exposure to container security and performance tuning on OpenShift. Knowledge of payment gateways, ISO 20022, or SWIFT formats. Location & Work Environment: Hybrid work model in London, UK. Collaborative, fast-paced, and engineering-driven culture. Emphasis on engineering autonomy, architectural decision-making, and clean code Join Our Global Team: We invite you to apply for the position at RE Partners. Join us in shaping the future of business technology consulting and transforming the way organizations thrive in a digital world.