Urgent - we are hiring senior Java profile / Solution Architect - experienced developerHappening is urgently looking for a Java expert to join one of our clients on strategic, high-impact projects.Your missionDesign, analyze, and develop Java / J2EE solutions aligned with functional and technical requirementsDefine and implement scalable, secure, and high-performing architectures (MicroServices, API-first, cloud)Ensure code quality through best practices (TDD, CI/CD, DevSecOps, code review)Collaborate with cross-functional teams in an Agile / Scrum environmentCoach and mentor developers when neededContribute to both new application development and the maintenance/evolution of existing systemsTechnical stack (non-exhaustive)Languages / Frameworks: Java, JEE, Spring, Spring Boot, Hibernate / JPA, Node.js (TypeScript), GWTAPI & Integration: REST, SOAP, JSON, XML, API design, Kafka, event-driven architectureFrontend: Angular, HTML, CSS, JavaScriptDatabases: PostgreSQL, Oracle, PostGIS, RDBMS, NoSQL, key-value storesTesting & Quality: JUnit, Assertj, Test Driven DevelopmentTools & Methodologies: Maven, GIT, Jira, Confluence, MiroCloud & DevOps: AWS, Azure, CI/CD pipelines, DevSecOpsSecurity: solid knowledge of security standards and best practicesProfile we are looking for5-9+ years of proven experience in Java development and/or architectureStrong expertise in Spring/Spring Boot, Hibernate, JPAProven experience in API design, integration, and distributed environmentsSolid knowledge of cloud architectures (AWS/Azure) and/or hybrid solutionsExperience in Agile / Scrum, ideally with a lead developer or Solution Architect roleStrong analytical mindset, autonomy, and excellent communication skillsPrevious experience in public sector projects is a strong plusLocation & setup: Hybrid mission: minimum 2 days per week on-site in BelgiumIf you are a seasoned Java expert with strong experience in development, architecture, and modern best practices, and want to join a challenging project with a rich technology stack: apply now!