Get AI-powered advice on this job and more exclusive features.

This range is provided by Fynity. Your actual pay will be based on your skills and experience — talk with your recruiter to learn more.

Base pay range

Direct message the job poster from Fynity

Practice Lead @ Fynity | Building Architecture and Product teams for leading orgs across the UK & Europe

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

• 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.

Seniority level

• Seniority level

  Mid-Senior level

Employment type

• Employment type

  Full-time

Job function

• Job function

  Consulting, Engineering, and Information Technology

• Industries

  Banking, Software Development, and IT Services and IT Consulting

Referrals increase your chances of interviewing at Fynity by 2x

Sign in to set job alerts for “Java Software Engineer” roles.

London, England, United Kingdom 1 month ago

London, England, United Kingdom 4 days ago

London, England, United Kingdom 11 hours ago

London, England, United Kingdom 1 day ago

Greater London, England, United Kingdom 2 weeks ago

London, England, United Kingdom 4 days ago

London, England, United Kingdom 2 weeks ago

London, England, United Kingdom 1 month ago

London, England, United Kingdom 1 month ago

Greater London, England, United Kingdom 1 week ago

London, England, United Kingdom 1 month ago

London, England, United Kingdom 1 year ago

London, England, United Kingdom 1 week ago

Java Software Engineer - Real-time Payments

London, England, United Kingdom 1 week ago

London, England, United Kingdom 2 weeks ago

Software Engineer (Java) - Up To £550 Per Day + Benefits - London

London, England, United Kingdom 1 week ago

St Albans, England, United Kingdom 1 week ago

Software Developer / Full-Stack Engineer (Java, Spring Boot, Microservices, NodeJS, React) – Hybrid Working

London, England, United Kingdom 2 days ago

London, England, United Kingdom 2 weeks ago

London, England, United Kingdom 1 week ago

London, England, United Kingdom 2 months ago

We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI.