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 do

• Design 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 qualifications

• Proven 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-have

• Experience 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 start

• Location: Brussels, Belgium (hybrid/remote options available)
• Start date: November

If 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.