Software Engineer - Java 21, Springboot Up to £550 per day (Inside IR35) London / Remote 6 months My client is an instantly recognisable consultancy who require a strong Backend Software Engineer with deep expertise in Java (Spring Boot) to join a large-scale, business‑critical microservices programme. All candidates must be eligible for Security Clearance (SC) Key Requirements: Proven experience working as a Java Software Engineer on large microservice architectures Strong experience building scalable backend and RESTful services using Java (Spring Boot) Ideally Java v21 (or very recent versions) Postgres (or other relational SQL databases) with a solid understanding of schema design and SQL Docker: confident containerising and deploying applications Test‑Driven Development (JUnit, Mockito, or similar testing frameworks) CI/CD: hands‑on experience with Jenkins or similar automated pipeline tooling Comfortable working in agile teams and collaborating closely with engineers and other disciplines Nice to have: Active Security Clearance (SC) Experience in coding-intensive environments (fintech, payments, digital banking, capital markets/trading) API specification using Swagger / OpenAPI Gradle build systems Liquibase (or similar) for database migrations/versioning Kafka or other event‑streaming platforms React and TypeScript If you're interested in this role, click 'apply now' to forward an up-to-date copy of your CV, or call us now. If this job isn't quite right for you, but you are looking for a new position, please contact us for a confidential discussion about your career. Hays Specialist Recruitment Limited acts as an employment agency for permanent recruitment and employment business for the supply of temporary workers. By applying for this job you accept the T&C's, Privacy Policy and Disclaimers which can be found at (url removed)