A major Belgian financial institution is evolving its backend platform toward microservices and reactive architectures to improve availability and performance. The role exists to design and deliver backend services in Java 21 using Spring and reactive programming, with responsibilities spanning API design (RESTful and SOAP), high availability and backward compatibility across releases.
The mission
The team maintains a portfolio of enterprise backend services that process business transactions and feed downstream systems. The technical landscape is microservices-based, with JVM services built on Java 21, Spring and Reactive Streams, CI/CD pipelines in Jenkins, and source control in Git. Work focuses on scalability, performance tuning and ensuring backward compatibility for clients that depend on stable APIs.
Day to day you will shape service design and implement production-ready microservices, own API contracts (RESTful API and SOAP API integrations), and contribute to architectural decisions around versioning, resilience and database design. You will work in an Agile team that follows SCRUM, collaborate with product owners and QA, and participate in on-call rotations to triage incidents and maintain service reliability.
Your responsibilities
- Lead design and delivery of backend microservices, producing reusable, versioned APIs that remain backward compatible
- Implement high-availability, resilient services in Java 21 using Spring and reactive programming, optimising for throughput and latency
- Drive CI/CD quality by writing automated unit and integration tests, configuring Jenkins pipelines and enforcing code review standards
- Define and maintain API contracts and documentation (OpenAPI, WSDL, XSD), and ensure consistent JSON/XML payloads across services
- Investigate and resolve production incidents, perform root cause analysis and implement preventive measures
- Mentor junior engineers, review code in Git, and help the team follow Agile practices and delivery cadences
Your profile
Essential skills
- 5+ years of backend development experience, with demonstrable work in Java (Java 21 preferred) and Reactive Streams
- Strong experience with Spring framework, RESTful APIs and SOAP/WSDL integrations
- Proven ability to design microservices with versioning, backward compatibility, resilience and performance in mind
- Practical experience with GIT, Jenkins, Maven, IntelliJ and Jira in a CI/CD environment
- Solid SQL skills and experience modelling relational schemas and writing performant queries
- Comfortable in Agile (SCRUM) teams, able to communicate technical trade-offs to product and operations colleagues
Languages
- French, B2 (working proficiency)
- Dutch, B2 (working proficiency)
- English, C1 (professional)
Education
- Master, Bachelor or equivalent professional experience