We are supporting a leading telecommunications provider on several business-critical digital initiatives, including large-scale platform modernization and customer-facing system evolution. We are looking for an experienced Backend Java Developer with a solid understanding of frontend technologies to join a modern, modular engineering environment.

Logistics

• Role: Freelance Backend Java Developer
• Contract: 12–24 months
• Location: Brussels (Hybrid - 2 days/week on-site)
• Languages: English + French or Dutch
• Start Date: ASAP / January
• Rate: Competitive & negotiable

Responsibilities

• Design, develop, and maintain scalable backend services using Java and Spring Boot
• Contribute to greenfield initiatives and long-term platform evolution projects
• Translate complex business and operational requirements into robust technical solutions
• Apply clean code, TDD, and collaborative development practices (pair programming)
• Support and evolve system architecture using DDD and hexagonal architecture
• Build and maintain solutions within CI/CD pipelines and containerized environments
• Participate actively in code reviews and agile ceremonies
• Collaborate with frontend teams when required to ensure end-to-end solution quality
• Work on high-throughput, highly available systems typical of telecom environments

Required Skills

• 6+ years of experience as a Backend Java Developer
• Strong expertise with Spring Boot
• Experience with Kafka or other event-driven / messaging systems
• Solid knowledge of REST APIs and relational databases (Oracle, PostgreSQL, or similar)
• Experience with Docker and Kubernetes
• Familiarity with CI/CD tooling (Git, GitLab, Jenkins, SonarQube)
• Working knowledge of frontend technologies (Angular, React, TypeScript)
• Comfortable working autonomously within Agile/Scrum teams
• Experience working on large-scale, distributed systems

Nice to Have

• Experience in the telecommunications industry (BSS/OSS, billing, provisioning, network-related systems)
• Exposure to legacy system modernization or modularization initiatives
• Knowledge of DevSecOps or security-by-design principles
• Experience working in Spotify-model or squad-based organizations
• Familiarity with high-availability, low-latency systems

Interested? Get in touch to discuss details and next steps.