Senior .NET Developer

Senior .NET Developer (Freelance) - 13 Months - Brussels (Schaerbeek) Belgium

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About the Role

RELYzIT Talent is seeking a Senior .NET Developer (Freelance) to join our client’s high-impact digital transformation initiative within the public sector. This is a 13-month freelance assignment based in Brussels (Schaerbeek), Belgium. You’ll be at the heart of a mission-critical project, driving the evolution of financial and budgetary processes through advanced technology. Your expertise will directly shape the digital backbone supporting vital business operations, ensuring seamless integration and future-ready solutions.

Why This Role Matters

Our client is on a journey to digitize and optimize financial operations, impacting everything from budget preparation and forecasting to document flows and cash management. As a Senior .NET Developer, you will be instrumental in building and enhancing the Budget and Consolidation Tool (BCT) platform, ensuring it remains robust, scalable, and aligned with evolving business needs. Your work will empower decision-makers, streamline complex workflows, and support the digital transformation of public sector finance.

What You’ll Be Doing

• Lead the technical analysis and design of new features based on functional requirements, collaborating closely with fellow developers.


• Efficiently execute programming tasks: coding, testing, debugging, and delivering high-quality, maintainable code.


• Develop and maintain .NET-based applications, web APIs, and integrations with Azure services.


• Coach and mentor team members, fostering a collaborative and high-performance development environment.


• Ensure code quality and documentation align with team standards (code guidelines, unit tests, technical documentation).


• Identify and communicate opportunities for technical improvement and innovation within the platform.


• Contribute to the integration of additional business processes into the BCT platform, supporting a growing range of financial operations.


• Operate independently or within small teams for focused development assignments and ongoing maintenance.


• Champion Agile methodologies, taking a leading role in iterative development and continuous improvement.

Technical Skills & Experience

• Senior-level experience in developing .NET-based applications (C#, ASP.NET).


• Proven expertise in building and maintaining web APIs.


• Strong experience with Azure Blob Storage, Azure Communication Services, Azure DevOps, and Azure Service Bus.


• Advanced proficiency with Microsoft SQL Server and Entity Framework.


• Solid experience with React (Medior level) and other SPA frameworks (Angular, Vue, Solid, Svelte).


• Demonstrable knowledge of object-oriented analysis & design and UML.


• Experience conducting technical analyses and translating functional requirements into robust technical solutions.


• Efficient in executing programming tasks: coding, testing, debugging, and delivering production-ready solutions.


• Experience leading development teams and coaching developers to achieve technical excellence.


• Familiarity with Agile development methodologies, with the ability to assume a leadership role.


• Experience working for or with the Flemish government is a strong plus.


• Experience with budgeting applications is a nice to have.

Education & Language Requirements

• Bachelor’s or Master’s degree in a relevant field (business economics or equivalent through experience).


• Demonstrable education with certification or equivalent experience in .NET (C#), ASP.NET, and related environments.


• Fluency in Dutch at European CEFR level C2 (mandatory).

Other Requirements

• Ability to operate independently on smaller assignments or as part of a limited team.


• Strong ownership mindset, proactive problem-solving skills, and a drive for impactful results.


• Commitment to delivering quality, maintainable code and clear documentation.


• Builder-first mentality: you see beyond tasks and are motivated by outcomes and impact.

This is a freelance position for 13 months, based in Brussels (Schaerbeek), Belgium. RELYzIT Talent is committed to connecting elite tech talent with roles that drive real-world impact and innovation. Join a community where your skills are valued, your expertise is recognized, and your contributions shape the future.