Senior Java EngineerBrussels, BelgiumLong term contractOverviewOur client is seeking a Senior Java Engineer with strong expertise in modern Java, cloud‑native development, and high‑throughput system optimisation. You will join a backend engineering team working on large‑scale, performance‑critical applications deployed in public cloud environments. The focus of the role is to build, tune, and optimise Java services to ensure reliability, scalability, and excellent runtime performance.This position is ideal for someone who enjoys deep technical problem‑solving, distributed systems, and hands‑on performance engineering.Key ResponsibilitiesDesign, develop, and maintain Java backend applications using modern frameworks and best practices.Build and optimise services using Java (JDK 21+), Java SE, Spring Boot, JMS, REST, and SQL.Implement high‑quality CI/CD pipelines with Jenkins, including unit, integration, and automated test orchestration.Work within containerised environments using Docker and Kubernetes.Develop and tune data‑intensive services interacting with Oracle and PostgreSQL databases.Design and maintain distributed microservices and event‑driven systems using Kafka and REST APIs.Operate and troubleshoot applications running on public cloud platforms (Azure preferred; AWS also relevant).Use infrastructure‑as‑code tooling such as Terraform to support cloud deployments.Apply strong monitoring, observability, and networking principles to ensure system stability.Perform performance profiling and tuning of high‑throughput, low‑latency applications.Collaborate closely with engineering teams to solve complex technical challenges.Contribute to technical discussions, architecture decisions, and best‑practice improvements.Required Skills & ExperienceTechnical SkillsStrong experience in Java application development.Excellent knowledge of:Java JDK 21+, Java SESpring BootJMS, REST, SQLPractical experience with Jenkins, CI pipelines, unit and integration testing, and test orchestration.Advanced knowledge of Docker and Kubernetes environments.Very good understanding of Oracle and PostgreSQL databases.Comfortable working in Linux environments.Knowledge of Kafka, RESTful APIs, and microservices architecture.Familiarity with public cloud platforms (Azure preferred) including Terraform, Kubernetes, networking, and monitoring tools.Hands‑on experience tuning high‑throughput, large‑scale systems deployed on cloud platforms (Azure or AWS).