Senior .NET Developer

Our client is looking for a senior .NET professional to help shape modern public-sector digital services with a strong focus on user experience, accessibility and technical quality. In this role, you will take ownership of both the Blazor front end and the .NET services behind it, contributing to secure, responsive and reusable business applications while also guiding fellow developers and supporting sound technical decisions.

Responsibilities

You will work across the full application lifecycle, combining hands-on delivery with technical leadership. The role includes close collaboration with analysts, architects, UX stakeholders, security specialists and operational teams to turn functional needs into reliable digital solutions.

• Provide technical direction for Blazor development and promote consistent front-end architecture, reusable components and coding standards.
• Develop new features, technical improvements, prototypes and bug fixes in C#, modern .NET, Blazor and Razor components.
• Design scalable and maintainable UI structures aligned with architectural principles and the shared component library.
• Build responsive and accessible interfaces that meet WCAG 2.1 AA requirements.
• Translate business and functional needs into robust technical solutions in collaboration with relevant stakeholders.
• Integrate applications with REST APIs and JSON-based services, and extend web APIs when needed.
• Implement secure authentication and authorization using OAuth 2.0 and OpenID Connect.
• Maintain high code quality through reviews, refactoring, static analysis and reusable, testable code.
• Define and maintain automated testing across unit, component, integration and UI levels.
• Use Git, Azure DevOps and CI/CD pipelines to support controlled delivery to Azure environments.
• Investigate and resolve complex issues across browser, API and database layers in different environments.
• Coach colleagues, share knowledge and contribute to continuous improvement across the team.
• Evaluate relevant technologies and patterns, including AI-assisted development practices, and advise on their value.
  
  
  

Technical Skills

The ideal candidate brings recent, substantial hands-on experience with modern .NET development and strong front-end expertise. The following technical background is expected:

• Advanced C# and modern .NET / ASP.NET Core development.
• Blazor and Razor components, including Blazor Web App render modes.
• Strong knowledge of HTML, CSS and responsive design.
• Practical experience with web accessibility and WCAG 2.1 AA.
• Experience consuming and building REST APIs with JSON exchanges.
• Experience with OAuth 2.0, OpenID Connect, JWT and claims-based authorization.
• Working knowledge of Entity Framework Core and SQL.
• Solid testing experience, including unit, component, integration and UI automation.
• Strong command of Git, Azure DevOps and CI/CD pipelines.
• Awareness of code quality, maintainability, security and observability best practices.
• Experience using AI-assisted development tools in a professional setting.
  
  
  

Additional knowledge is considered an asset, including Microsoft Azure, containerised environments, JavaScript or TypeScript interoperability, messaging solutions such as Azure Service Bus or NServiceBus, and maintenance of legacy .NET applications.

Profile

We are seeking a developer who can work autonomously on complex challenges while remaining deeply involved in delivery. You should be able to make practical technical decisions, support others through coaching and reviews, and keep a clear focus on secure, accessible and user-friendly outcomes.

• Strong analytical and problem-solving skills.
• Ability to work effectively with multidisciplinary teams.
• Clear communication with both technical and non-technical stakeholders.
• Comfortable translating user needs into efficient digital experiences.
• Hands-on mindset with proven senior delivery experience.
• Interest in continuous learning and applying modern engineering practices.
  
  
  

Practical Information

• Language requirements: fluent Dutch, French or Dutch, and professional English. Passive understanding of the other national language.
• Work arrangement: at least two days per week on-site in Brussels, with telework permitted within Belgium.
  
  
  

Contactperson & Reference

• Reference #: INW28851
• Marilyn Weytens
• marilyn.weytens@i4m.be