Senior .NET Developer

You will join a large-scale application modernisation program within the Employee Benefits domain. Several legacy applications are being rebuilt on a modern .NET-based technology stack, with a strong focus on clean architecture, maintainability, and long-term scalability.

You work closely with internal teams and external delivery partners to redesign existing application capabilities and bring them to life in the target environment. This is a hands-on senior role for someone who enjoys combining technical leadership with real development work.

What you'll do

• You co-create and review application designs for modernized systems, ensuring they are clear, consistent, and aligned with architectural standards.
• You guide and coach the offshore design and development team, helping them understand both the business domain and the technical design choices.
• You perform code reviews to safeguard code quality, architecture consistency, and overall software design.
• You actively support the development team during implementation through design explanations, peer programming, and hands-on technical guidance.
• You collaborate closely with business analysts and solution architects to translate requirements into robust and pragmatic application designs.
• You design and develop selected features yourself, staying hands-on where it adds value.
• You support testing activities, both during system testing and user acceptance testing, to ensure solutions behave as intended.

What are we looking for?

• You have solid experience with
  object-oriented programming in .NET Core
  and feel comfortable designing modern applications.
• You have hands-on experience designing and implementing
  RESTful APIs
  , following a resource-based approach.
• You are familiar with
  Domain-Driven Design
  and
  Clean Architecture
  , and you understand how to apply these concepts pragmatically.
• You have experience with
  event-driven architectures
  , UML design, and relational database modeling.
• You communicate clearly, can explain design choices, and are comfortable presenting and defending technical decisions.
• You work in a structured, proactive way and take ownership of your work, while remaining a strong team player.
• You are fluent in
  English
  and
  French
  . You have a good working knowledge of
  Dutch
  , which is a strong asset

Nice to have

• You have experience with
  Azure Service Bus
  or messaging-based integrations.
• You have been exposed to
  Kubernetes
  environments.

What do we offer?

Location:
Brussels

Start date:
As soon as possible

Duration:
12 months (extension possible)

Contract:
Freelance or Permanent