Principal Developer – Full-Stack with AI

Contract Duration: 1 year Initial contract-Self Employed

Brussels Hybrid (once in a week)

Key Responsibilities:

Full-Stack Architecture & Development: Lead the design and development of end-to-end solutions with a strong emphasis on Java backend services using Quarkus/Spring, while also developing modern, responsive frontend applications using React, TypeScript, and contemporary UI frameworks. Ensure architectural coherence across the entire stack.

AI-Assisted Development: Champion the adoption and effective use of Claude Code and other AI-assisted development frameworks. Guide the team in prompt engineering, code review of AI-generated code, and best practices for integrating AI tools into the development workflow while maintaining security and quality standards.

Backend Excellence: Architect and implement high-performance, scalable microservices and APIs using Java, ensuring code is maintainable, testable, and aligned with industry best practices. Drive technical decisions on backend architecture and patterns.

Database Architecture: Design and optimize complex database solutions across MongoDB and PostgreSQL, including schema design, query optimization, indexing strategies, data modeling, and migration strategies to achieve exceptional performance and scalability.

Event-Driven Architecture: Design and implement robust event-driven systems using Kafka, ensuring reliable message processing, event sourcing patterns, and seamless integration with monitoring solutions (ELK stack).

Performance & Scalability Engineering: Identify, analyze, and resolve performance bottlenecks across the entire stack - from frontend rendering to backend processing to database queries. Implement comprehensive performance monitoring, profiling, and optimization strategies.

DevOps & CI/CD Leadership: Design and maintain sophisticated CI/CD pipelines using Jenkins, integrate security scanning (SonarQube, Snyk, OWASP), manage artifact repositories (Nexus), and ensure deployment automation. Implement infrastructure-as-code and container orchestration strategies.

Testing Strategy: Establish comprehensive testing strategies including unit testing, integration testing, end-to-end testing, performance testing, and security testing. Ensure high code coverage and quality gates throughout the pipeline.

Security & Compliance: Implement and enforce security best practices across the full stack, including secure coding, authentication/authorization mechanisms, vulnerability management, secrets management, and compliance with industry standards.

Technical Leadership: Provide technical mentorship to development teams, conduct code reviews, establish coding standards, and foster a culture of engineering excellence and continuous learning. Make critical architectural decisions and drive technical strategy.

AI/ML Integration: Design and implement integrations with AI/ML services, LLM APIs, and intelligent automation features. Understand prompt engineering, model selection, and responsible AI practices.

Stakeholder Collaboration: Work closely with product owners, architects, security teams, and business stakeholders to translate complex requirements into technical solutions. Communicate technical concepts effectively to both technical and non-technical audiences.

End-to-End Ownership: Take complete ownership of complex features and systems from conception through design, implementation, testing, deployment, and maintenance. Drive initiatives independently with minimal supervision while ensuring alignment with team goals.

Skills & Qualifications:

Required Technical Expertise:

• Java Mastery: 8+ years of extensive experience with Java, Maven/Gradle, and deep expertise in Quarkus and/or Spring Boot for building enterprise-grade applications. Strong understanding of JVM internals, garbage collection, and performance tuning.
• Full-Stack Proficiency: Strong experience with React, TypeScript/JavaScript (ES6+), HTML5, CSS3, and modern frontend build tools (Webpack, Vite). Experience with responsive design, state management (Redux, Context API), and frontend performance optimization.
• Database Expertise: Advanced knowledge of MongoDB and PostgreSQL, including complex query optimization, indexing strategies, replication, sharding, backup/recovery, and data migration patterns.
• Microservices & Messaging: Expert-level experience with Kafka for event-driven architectures, including topics, partitions, consumer groups, and integration with monitoring solutions (ELK stack, Prometheus, Grafana).
• DevOps & Infrastructure: Strong hands-on experience with Docker, Kubernetes, Jenkins, SonarQube, Nexus, and GitOps practices. Ability to design and implement complete CI/CD pipelines with security integration.
• Version Control: Advanced Git proficiency, ideally with Bitbucket, including branching strategies, merge conflict resolution, and code review processes.
• Cloud & Infrastructure: Experience with cloud platforms (AWS, Azure, or GCP), infrastructure-as-code (Terraform, Ansible), and container orchestration at scale.
• AI & LLM Integration: Practical experience with AI-assisted development tools (Claude Code, GitHub Copilot, or similar). Understanding of LLM APIs, prompt engineering, and integration patterns. Knowledge of AI/ML frameworks (TensorFlow, PyTorch, scikit-learn) is a plus.
• Testing Frameworks: Comprehensive knowledge of testing strategies and tools including JUnit, Mockito, Testcontainers, Jest, React Testing Library, Selenium/Cypress, and performance testing tools (JMeter, Gatling).
• Security Tools & Practices: Experience with security scanning tools (Snyk, OWASP Dependency-Check), secure coding practices, authentication/authorization (OAuth2, JWT, OIDC), and vulnerability management.
• Performance Engineering: Deep understanding of performance profiling tools (JProfiler, VisualVM, Chrome DevTools), APM solutions (New Relic, Dynatrace, AppDynamics), and optimization techniques across the entire stack.

Required Professional Attributes:

• Principal-Level Experience: 10+ years of software development experience with at least 3-5 years in senior or principal roles, demonstrating technical leadership and strategic thinking.
• Architectural Vision: Proven ability to design complex, scalable systems and make sound architectural decisions that balance technical excellence with business needs.
• Exceptional Communication: Outstanding ability to articulate complex technical concepts to diverse audiences, lead technical discussions, and build consensus across teams.
• Agile Mastery: Deep experience with Agile/Scrum methodologies, with the ability to mentor teams on best practices and continuous improvement.
• Autonomous Leadership: Demonstrated ability to work independently, drive initiatives from conception to completion, and make critical decisions with minimal supervision while keeping stakeholders informed.
• Mentorship Excellence: Proven track record of mentoring developers, conducting effective code reviews, and elevating team capabilities through knowledge sharing.
• Innovation Mindset: Passion for emerging technologies, particularly AI-assisted development, with the curiosity and drive to evaluate and adopt new tools and practices that enhance team productivity.
• Problem-Solving Excellence: Strong analytical skills with the ability to break down complex problems, identify root causes, and implement elegant, maintainable solutions.
• Continuous Learning: Commitment to staying current with industry trends, best practices, and emerging technologies through continuous learning and professional development.

Preferred Qualifications:

• Experience with additional frontend frameworks (Vue.js, Angular)
• Knowledge of GraphQL and API design patterns
• Familiarity with observability platforms and distributed tracing
• Experience in the aviation or air traffic management domain
• Understanding of AIXM (Aeronautical Information Exchange Model) or aeronautical data standards
• Contributions to open-source projects or technical community engagement
• Certifications in relevant technologies (AWS, Kubernetes, Java, etc.)