We currently have a vacancy for a Senior Back-End Engineer (Java / Kotlin) fluent in English, to offer his/her services as an expert who will be based in Belgium. The work will be carried out either in the company's premises or on-site at customer premises. In the context of the first assignment, the successful candidate will be integrated with the Development team of the company that will closely cooperate with a major client's IT team on site. Your tasks Development of back-end website applications; Integration ofuser-facing elements developed by a front-end developer with server side logic; Creationof servers and databases for functionality; Design and implementation of data storage solutions; Understanding and implementation of security and data protection; Design and develop APIs; Compile and analyse data, processes, and codes to troubleshoot problems and identify areas for improvement; Testing and fixing bugs or other coding issues; Write technical documentation. Requirements University degree in IT combined with relevant IT professional experience of 15 years; At least10 years of expertise in Vert.X, Kotlin, Java (> 17), Spring Boot (WebFlux), Hibernate; ; At least10 years of experience in Collaboration & Productivity Tools: JIRA, Confluence, Office 365, SharePoint; At least6 years of expertise in Architecture & Integration: Microservices Architecture, API-driven Development, AS4; At least6 years of specific expertise in Containerization & Orchestration: Docker, Kubernetes; At least6 years of experience in Security Testing & Dependency Management: SAST, DAST, Fortify, SonarQube, Sonatype, Dependency-Track, Maven; At least6 years of expertise in Databases: MongoDB, PostgreSQL, Virtuoso Triple Store, OpenSearch At least 5 years of experience in Security: OpenID Connect, OAuth2, TLS, Keycloak Excellent command of the English language.