Principal Java Developer

RE Partners Consulting; Greater London; On-site; GBP 36,216 - 144,864; Full time

Benefits offered by this job

Referral bonus

Competitive salary

Diverse, inclusive workplace

Job summary

A technology consulting firm is seeking a Principal Java Engineer to join their team in London. The ideal candidate will have over 10 years of experience in Java development, particularly with low-latency systems in payments processing. Responsibilities include designing backend systems, building RESTful APIs, and collaborating across teams to ensure optimal performance. With a hybrid work model and a commitment to employee satisfaction, this role offers a competitive salary in the range of $50,000 to $200,000 per year.

Qualifications

• 10+ years of experience in Java development focusing on performance.
• Proficient in Mongo, Spring, and microservice-based architecture.
• Experience with low-latency, high-throughput applications.

Responsibilities

• Design and develop low-latency backend systems using Java.
• Build and maintain RESTful APIs for secure payment workflows.
• Work with messaging standards in financial transactions.

Skills

Core Java

Spring

Low-latency application development

Microservices architecture

AWS services (ECS, EKS, Lambda, S3)

MongoDB

Kubernetes

Messaging systems (Kafka, RabbitMQ)

Job description

Who We Are:

We are a fast growing business and technology consultant company co-founded in 2019. We offer a custom‑tailored, white‑glove engineering service fit for our clients, because a digital transformation is more than just technology. With a successful track record of being a preferred vendor for Fortune 500 companies and as a trusted partner for some of the industry’s leading companies, our global talent has helped many clients achieve their goals.

The 3 G’s of RE:

“Get Shit Done.”

“Get Over Shit.”

“Give a Shit.”

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 or US 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.
• 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. As a diverse, woman‑owned global business, we pride ourselves on keeping talent happy – our 7% attrition rate speaks volumes. Bring your talented friends along and earn a referral bonus.

Equal Opportunity Employer:

We are an equal opportunity employer and welcome applications from all qualified individuals regardless of race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, disability, or veteran status.

Salary Range:

The base salary range for this role is $50,000–$200,000 per year. This is our good‑faith estimate at the time of posting. Actual base pay will depend on factors such as skills, experience, and location. This role may also be eligible for additional compensation (e.g., bonus/equity) and benefits, as applicable.