End-to-End Engineer / Fullstack Developer

Location: Brussels, Belgium (Hybrid — 50% onsite)

Industry: Aviation & Air Traffic Management

Contract Type: Freelance / Long-term assignment

About the Role

We are seeking an experienced End-to-End Engineer / Fullstack Developer to work on large-scale, mission-critical systems within the aviation and air traffic management sector. You will be responsible for delivering robust, high-performance full-stack solutions with a strong emphasis on backend development, frontend architecture, and DevOps best practices.

Key Responsibilities

• Software Development: Design and build scalable Java applications (Quarkus/Spring), ensuring maintainability and efficiency.
• Database Optimization: Architect and optimize MongoDB and PostgreSQL schemas, queries, and indexing strategies for performance and scalability.
• Microservices & Messaging: Develop and scale microservices using Kafka, with ELK stack integration for monitoring and troubleshooting.
• Performance Engineering: Identify and resolve performance bottlenecks at code and infrastructure levels.
• DevOps: Manage CI/CD pipelines using Jenkins, SonarQube, Nexus, Docker, and Kubernetes.
• Security: Implement secure coding practices and ensure compliance with security standards.
• Frontend Development: Develop modern and responsive interfaces using React (with TypeScript), Ant Design, Webpack, and testing with Jest and React Testing Library.
• Ownership: Drive solutions end-to-end with minimal supervision, including codebase takeover and delivery.
• Collaboration: Work closely with product owners, architects, and other stakeholders.
• Mentorship: Support and guide junior developers.

Required Skills & Experience

• Strong Java expertise with Quarkus and/or Spring.
• Proficiency in MongoDB, PostgreSQL, Kafka, and ELK stack.
• Proven DevOps skills with Kubernetes, Docker, Jenkins, SonarQube, and Nexus.
• Solid understanding of performance optimization and profiling.
• Security best practices implementation.
• Hands-on frontend experience with React, TypeScript, and modern JS.
• Familiarity with MinIO storage, JWT, and RBAC concepts.
• Agile methodology experience.
• Excellent communication and problem-solving skills.
• Proactive and independent work ethic.

Additional Information

• Start Date: Immediate or flexible
• Location: Brussels, Belgium — 50% onsite
• Duration: Long-term assignment
• Meetings: Integration review after 1 month, quarterly progress reviews, bi-annual evaluations