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Job Description

Principal Software Engineer (Java)

London – 1 day a week onsite

Join a FinTech Powering the Future of Payments

Are you a seasoned individual contributor looking for a step up into a senior position within a high-performing team within the world of Banking/Payments? Are you passionate about high-throughput, real-time systems? This is your opportunity to help shape the core technology that powers instant payments for some of the world’s largest Banks.

We’re hiring on behalf of a leading payments consultancy, delivering cutting-edge solutions that integrate seamlessly with bank infrastructure to enable real-time, secure transactions across the globe.

What You’ll Be Doing

You’ll be the focal point of a high-performing engineering team building asynchronous, event-driven systems using modern Java technologies.

Design and build scalable, high-availability systems processing millions of real-time transactions Work with Java 17+, Spring WebFlux, AKKA, Kafka, and more Write clean, testable code using TDD and BDD Contribute to architectural decisions in a fast-evolving codebase Collaborate within Agile teams (Kanban/Scrum)

What You Bring

We’re looking for engineers who are pragmatic, performance-focused, and thrive on solving complex distributed systems problems.

Strong hands-on experience with Java 11+ (ideally Java 17) Solid knowledge of Reactive Programming (e.g., Spring WebFlux, AKKA) Experience with event-driven architecture, real-time messaging systems (Kafka, JMS) Familiarity with asynchronous request handling, scalability, and system resilience Agile mindset, with TDD/BDD and CI/CD experience

Bonus: Background in Banking/Payments is helpful but not required – if you’ve built high-performance, real-time systems, we want to talk to you.

What’s In It for You

£100,000 – £115,000 base salary (DOE) 20% bonus Work with cutting-edge tech on globally impactful systems Hybrid working – 1 day a week (or more if you’d like!) Opportunity to collaborate with major global banks Fast-paced, product-led environment where your voice matters

If you're a motivated Senior/Principal/Staff Java Software Engineer ready to tackle complex challenges and deliver meaningful change, hit apply – and shape the future of payments with us.

If you are interested in applying for this job please press the Apply Button and follow the application process. Energy Jobline wishes you the very best of luck in your next career move.