OneSource Consulting
Senior Java Software Engineer
OneSource ConsultingBelgium3 days ago
Full-timeInformation Technology

Job title: Java Full Stack Developer

Location: Brussels, Belgium

Language: French or Dutch and English

Duration: 01/06/2026-31/12/2026 with extension to long term


Job description:

As a Java Developer, you will be responsible for designing, developing, and optimizing enterprise and microservices-based solutions within a complex and scalable IT environment. You'll work on integration and migration projects, build robust REST architectures, and ensure continuity, data consistency, and high code quality throughout the entire software development cycle.

Responsibilities

  • Develop Java and Spring Boot-based microservices, including REST APIs, error handling, caching, and resilience mechanisms.
  • Building scalable, stateless services with attention to versioning, horizontal scalability and robust exception handling.
  • Design and maintain logging, monitoring and observability strategies, including use of APM data for technical decisions.
  • Setting up, improving and monitoring quality mechanisms in CI/CD environments (unit/integration tests, static analysis, coverage, security scans).
  • Optimize Angular applications with modern performance strategies (OnPush, lazy loading, bundle optimization).
  • Integration with messaging systems, including management of queue persistence, acknowledgements, transactions, and replication strategies.
  • Secure management of configuration and secrets in Kubernetes environments, including encryption, rotation, and external secret managers (Vault).
  • Monitoring and analyzing database performance in production and implementing structural improvements.
  • Apply secure-coding principles and mitigations for OWASP Top 10 vulnerabilities.

Technical Skills:

  • Minimum 5 years of experience
  • In-depth knowledge of Java, Spring Boot, and microservices architectures
  • Ervaring met REST‑design, resilience patterns, versioning en distributed systems
  • Knowledge of Angular, TypeScript and modern frontend optimization techniques
  • Ervaring met CI/CD pipelines, static analysis, automated testing, security scanning
  • Kubernetes‑ervaring: secrets management, environment separation, encryptie, Vault
  • Knowledge of messaging technologies (persistent queues, transactions, replication)
  • Monitoring & observability tooling (APM, logs, metrics)
  • Experience with database performance analysis
  • Strong knowledge of OWASP principles and secure coding

Key Skills

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