Senior Java Engineer

Description Role: Senior Java Engineer (Contract) Location: London, UK (On-site presence required) Duration: 3-6 Months The Project Our Client are undertaking a critical digital transformation project to migrate their business banking customers from a legacy retail product to their modern commercial platform. The Role We are seeking two highly skilled Senior Java Engineers to join our team for an initial 3-6 month contract. You will be instrumental in enhancing our backend capabilities and improving the velocity of our development teams. A key focus of this role will be to help us transition from traditional development practices to a more automated, "spec-based development" approach using agentic AI for code generation. Your primary responsibility will be to lay a solid foundation for our new microservices architecture, creating patterns and frameworks that our junior developers can follow. This is a hands-on role that also requires a strategic mindset to help us refactor our existing codebase to make it compatible with AI-driven development tools. Key Responsibilities * Develop and enhance backend microservices using Java and Spring Boot. * Work on a project migrating business banking customers to a new commercial platform. * Champion the adoption of agentic AI and spec-based development to accelerate our software delivery lifecycle. * Refactor existing Java applications to make them suitable for AI-powered code generation and improvement. * Mentor and guide a team of junior developers, providing clear frameworks and patterns for them to follow. * Design and build robust backend-for-frontend (BFF) services to support our web and mobile applications. * Collaborate with cross-functional teams to define, design, and ship new features. Skills and Experience * Expert-level knowledge of Java (version 21) and the Spring Boot framework (version 3.6+). * Proven Experience designing, building, and maintaining complex distributed systems and microservices architectures. * Strong hands-on Experience with cloud platforms, specifically AWS, and containerization technologies like Kubernetes (EKS). * A solid understanding of the full development lifecycle, including packaging (Maven), testing (JUnit, Mockito, Cucumber), and deployment (Argo CD). * Familiarity with agentic AI, code generation tools, or a strong personal intere...