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.