Senior Java Developer - Payment Platform

We are working with a fast-growing, established name in the payments space within iGaming, looking for a Senior Java Developer to take ownership of complex payment-platform components.
This is a business that has invested heavily in its engineering function, building secure, scalable systems that underpin its international operations, and the role offers genuine scope to shape how those systems evolve.
The role: you'll design and build scalable payment services and APIs, solving distributed-systems challenges and working closely with Leads and Architects to deliver secure, high-performing solutions. It would suit an experienced Java developer who enjoys ownership, values clean architecture, and wants exposure to complex, security-critical systems at scale, with the chance to mentor others along the way.

Responsibilities:

• Design and develop scalable payment services and APIs using Java and Spring Boot
• Apply SOLID principles and modern architecture and design patterns to build clean, maintainable solutions
• Design and optimise data solutions across PostgreSQL, MySQL, Hibernate/JPA and Redis
• Build event-driven, asynchronous processing using Kafka and RabbitMQ
• Design secure REST APIs, applying JWT, OAuth 2.0/2.1, authentication/authorisation and API security best practice
• Apply cryptographic and OWASP principles to ensure secure data handling
• Develop robust unit, functional and integration tests using JUnit and Mockito
• Own build and release processes across Maven/Gradle, CI/CD and containerised deployments
• Investigate complex production issues and lead cross-service root-cause analysis
• Drive refactoring, performance and reliability improvements, and lead code reviews
• Collaborate with Leads, Architects, Product and business stakeholders, and mentor junior developers

Requirements:

• 4–8 years' professional Java development experience, ideally including Java 18–25
• Strong experience with Spring/Spring Boot, REST APIs and Hibernate/JPA
• Solid understanding of distributed systems, databases, messaging and caching (Kafka/RabbitMQ, PostgreSQL/MySQL, Redis)
• Strong grasp of API security, OAuth 2.0/2.1, JWT and OWASP practices
• Experience with Maven/Gradle, CI/CD, Docker and cloud deployment
• Strong problem-solving and production troubleshooting skills
• Payments/FinTech experience highly desirable
• Bachelor's degree in computer science or equivalent experience