Senior Backend Engineer (Java/Microservices)

Senior Back-End Software Engineer (Java / Microservices)

Contract/freelance - hybrid in Brussels

Remit

• Develop and maintain back-end web applications, server-side modules, and core business logic
• Design, build, and secure RESTful APIs and web services (using OpenAPI/Swagger specifications)
• Design and implement relational database components, schemas, complex SQL queries, and data pipelines
• Integrate user-facing elements created by front-end developers with server-side logic
• Apply data and security best practices, including input validation, authentication/authorization, and compliant logging/monitoring
• Optimize applications for maximum speed, scalability, performance, and code integrity
• Write, execute, and maintain automated unit and integration tests (JUnit, Mockito) integrated into CI/CD pipelines
• Set up, query, and utilize Application Performance Monitoring (APM) tools to troubleshoot incidents and optimize lower environments
• Perform code reviews, technical onboarding, mentoring, and effort estimation
• Lead Agile/Scrum development teams of 5 to 10 members where required
• Author clear technical documentation and administrative progress reports

Skills

• Languages & Frameworks: Proficiency in Java (Spring Boot, Hibernate, JEE, EJB) as well as PHP, Python, or Node.js
• Application Servers & Messaging: Hands-on experience with WebLogic, EJB, and Apache Kafka
• Databases: Advanced experience with relational databases (Oracle, PostgreSQL, MySQL, PL/SQL) and NoSQL stores (MongoDB, CouchDB, CosmosDB)
• API Management: Experience with API Gateways, Postman, and RESTful web service architecture
• Containerization & Cloud: Proficiency with Docker, Kubernetes, and basic cloud back-end configurations (serverless functions, storage accounts)
• Build & CI/CD Pipelines: Practical experience using Git (GitFlow), Maven, GitLab, Jenkins, Bamboo, and Nexus
• Code Quality & ALM: Usage of SonarQube, SonarLint, HP Fortify, Jira, Bitbucket, and wikis
• Monitoring & Observability: Familiarity with APM tools (Dynatrace, Splunk, Elastic APM) and OpenTelemetry

Desirable

• Knowledge of business workflow orchestration engines (e.g., Camunda, Activiti)
• Experience applying AI tools to coding (e.g., Amazon Q, Kiro)
• Industry certifications such as AWS Certified Developer Associate, Azure Developer Associate, or CKAD
• Knowledge of public grants management, audit processes, or open-source reusable frameworks

For immediate consideration, please send me your latest CV