Application Developer (Freelance) – 12 Months – Brussels

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About the Role

We are seeking a versatile Application Developer (Freelance) to join our client’s Embedded Systems team for a 12-month mission. You’ll be at the heart of a project that is transforming public transport technology, developing and maintaining next-generation features for embedded platforms that power thousands of vehicles. Your work will directly impact the efficiency, sustainability, and user experience of public mobility across the region.

Why This Role Matters

Our client is on a mission to deliver smarter, more sustainable, and user-friendly public transport. With over 2,700 vehicles equipped with evolving embedded systems, your expertise will help shape the future of urban mobility. This role is critical in ensuring that new functionalities are not only developed but also seamlessly integrated and maintained, driving real-world impact for millions of users.

What You’ll Be Doing

• Collaborating within the Embedded Systems team to design, develop, and enhance applications for operational support and embedded platforms.
• Participating in feasibility studies and pre-implementation analysis for new features and system upgrades.
• Developing and maintaining shared applications impacting both operational support systems and embedded platforms.
• Building and optimizing microservices and real-time data flow analysis for high-performance, scalable solutions.
• Working with relational and big data databases to ensure robust data management and analytics.
• Contributing to the continuous evolution of embedded technology to meet emerging client and user needs.

What We’re Looking For

• Proven experience in web application development, with a builder’s mindset and a passion for problem-solving.
• Ability to communicate clearly and effectively, both in writing and in person.
• Ownership mentality — you take initiative and drive projects to impactful outcomes.
• Experience working in public sector or large-scale, mission-driven environments is highly valued.

Technical Skills

• Confirmed expertise in PHP, HTML, Symfony, JavaScript, Node.js, and Web Workers.
• Experience with C and C++ (nice to have for C, junior level for C++).
• Strong knowledge of relational databases (MySQL, MariaDB) and SQL.
• Hands-on experience with Elasticsearch and Grafana for big data analytics.
• Understanding of embedded platforms and real-time data flow analysis.
• Familiarity with Azure DevOps and Linux environments (junior level for Linux).

Language Proficiency

• French: Native proficiency required
• English: Nice to have

Other Requirements

• Hybrid work model (onsite and remote flexibility)
• Confirmed experience in the public sector is a strong advantage
• Immediate availability preferred

Ready to build the future? Upload your CV and join the movement of elite builders with RELYzIT Talent.

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