Senior Java Software Engineer

We are seeking a highly capable Java Developer to join our client’s team in Brussels. You’ll design and deliver high-performance, scalable Java applications using Java, Maven, and frameworks like Quarkus or Spring. You’ll work closely with product owners, architects, and cross-functional teams to drive end-to-end delivery in an agile environment.What you’ll doDesign and develop high-performance, scalable Java applications using Java, Maven, and frameworks such as Quarkus or Spring.Architect and optimize MongoDB and PostgreSQL schemas, queries, and indexing to ensure low latency and high throughput.Build and scale microservices and event-driven systems using Kafka; integrate with the ELK stack for logging, monitoring, and troubleshooting.Identify bottlenecks and lead performance optimization across code and database layers; implement profiling and tuning strategies.Drive DevOps practices: CI/CD pipelines with Jenkins, SonarQube, and Nexus; focus on automation, security, and deployment efficiency.Implement secure coding practices, vulnerability management, and compliance throughout the development lifecycle.Collaborate with product owners, architects, and engineers to understand requirements and deliver effective solutions.Mentor junior developers, sharing knowledge and fostering a culture of continuous improvement.End-to-end ownership: analyze, design, implement, test, and deploy tasks with minimal supervision; take ownership of codebases as needed.Engage in stakeholder interactions to provide technical insights and ensure alignment with business goals.Maintain a strong focus on quality, delivering robust software in iterative cycles.Required qualificationsProven experience with Java, Maven, and building large-scale applications using Quarkus or Spring.Strong experience with Git; familiarity with Bitbucket is a plus.Deep expertise with MongoDB and PostgreSQL, including performance-oriented data access and indexing.Expertise in Kafka for building event-driven systems; integration with the ELK stack for monitoring and troubleshooting.Deep understanding of performance optimization and profiling techniques for both code and database layers.Proficient with Docker, Kubernetes, Jenkins, SonarQube, and Nexus for DevOps and CI/CD pipelines.Ability to implement secure coding practices, vulnerability management, and compliance.Excellent soft skills: requirement analysis, effective communication with cross-functional teams, and initiative to drive tasks to completion.Solid experience with Agile methodologies and delivering software in iterative cycles.Proactive and independent mindset, capable of taking full responsibility for end-to-end delivery.Exposure to performance profiling tools and security tools (e.g., Snyk, OWASP).Knowledge of authentication/authorization concepts (e.g., JWT, RBAC) is a plus.Nice-to-haveExperience with additional cloud environments and related tooling (AWS/Azure/GCP).Experience taking ownership of codebases with limited handover.Familiarity with additional monitoring and security tooling beyond the core stack.Location and startLocation: Brussels, Belgium (hybrid/remote options available)Start date: NovemberIf you’re excited by building scalable, secure Java solutions and leading end-to-end delivery from design to deployment, we’d love to hear from you.