You will take technical ownership within a dedicated application team, responsible for both the evolution of existing systems and the delivery of new initiatives. The role combines hands-on development with architectural responsibility, acting as the technical anchor between developers, analysts, architects, and infrastructure teams.
You operate close to the code while ensuring alignment with enterprise architecture standards and operational constraints. Your work directly supports business-critical applications with a strong societal impact.
What you'll do
* Provide day-to-day technical leadership within the application team, guiding developers through design decisions, implementation choices, and best practices.
* Take end-to-end technical responsibility for the applications in your portfolio, covering development, deployment, maintenance, and evolution.
* Actively contribute to development work by coding features, fixing defects, and addressing complex technical challenges.
* Translate functional and non-functional requirements into robust, secure, and maintainable technical solutions in close collaboration with analysts and business stakeholders.
* Design scalable system architectures that align with broader architectural guidelines while making pragmatic, application-level design decisions.
* Prepare and maintain technical documentation for releases, including technical designs, deployment notes, and infrastructure-related deliverables.
* Coordinate configuration and change requests with Infrastructure & Operations teams to ensure system stability and performance.
* Review code and enforce quality standards through structured reviews, testing practices, and continuous improvement.
* Evaluate new technologies and frameworks where relevant, ensuring they fit within architectural and operational constraints.
* Lead the resolution of complex incidents and production issues, acting as the technical escalation point when needed.
* Collaborate closely with the portfolio architect to ensure consistency with strategic architecture while retaining ownership of application-level technical decisions.
What are we looking for?
* You have strong experience as a Technical Lead or Senior .NET Developer in complex application environments.
* You are highly proficient in
C# and .NET (.NET Core and modern .NET versions)
and have extensive experience building
ASP.NET Web APIs
.
* You have hands-on experience with
authentication and authorization mechanisms
, including
JWT, OAuth2, OpenID Connect, and claims-based security
.
* You are comfortable working with
Azure services
, including messaging components such as
Azure Service Bus
, and understand cloud-native design considerations.
* You have experience building user-facing components using
Blazor
or similar modern frontend technologies.
* You apply proven
design patterns, architectural principles, and coding best practices
in your daily work.
* You have solid experience with
RESTful APIs
, including proper API documentation using
Swagger / OpenAPI
.
* You work confidently with
SQL Server
and understand data access patterns, performance considerations, and transactional integrity.
* You apply
unit and integration testing
consistently to ensure reliability and maintainability.
* You are comfortable working with
Git-based workflows
and collaborating in structured DevOps environments.
* You understand core
networking concepts
and how application behavior interacts with infrastructure and security constraints.
* You communicate fluently in
Dutch, French, and English
, and can collaborate effectively with both technical and non-technical stakeholders.
What do we offer?
Location: Brussels (on-site)
Start date: January 2026
Duration: Until end of 2026
Contract: Freelance or Permanent