Senior .NET Developer

Description

The company runs a complex, business-critical application landscape and needs a Senior.NET Technical Developer for a long-term assignment.

You will join the team that keeps developing and evolving a large internal platform with a long history. Alongside building new features, you will help improve its architecture, performance, security and maintainability.

The role suits someone who takes ownership, likes technical challenges and enjoys improving complicated application environments.

Freelance contract. Full-time. Short-term start possible, with stable prospects beyond that.

Location: Flemish Brabant / Brussels Region. Hybrid, with 3 days onsite.

The company invites a confidential conversation with experienced.NET professionals who want to have real impact in a demanding, changing environment.

Responsibilities

• Write code hands-on within a.NET environment.
• Review the existing architecture and propose improvements.
• Lower technical debt and lead refactoring work.
• Find and fix performance and security problems.
• Advise on technical choices and modernization efforts.
• Design solutions that will hold up over time within the current environment.
• Challenge technical stakeholders and guide them.
• Work closely with business stakeholders and development teams.
• Take part in migration and continuous improvement programs.

Requirements

• You are a senior developer with a strong architecture background who still likes to be hands-on in development.
• At least 10 years of experience in Microsoft development environments.
• Strong knowledge of C# and.NET.
• Experience with ASP.NET MVC.
• In-depth knowledge of.NET Framework environments.
• Experience with modern.NET (.NET 6/7/8).
• Strong SQL Server skills.
• Experience with REST APIs and systems integration.
• Experience working in complex legacy environments.
• Proven track record in modernization and migration projects.
• Strong analytical and problem-solving skills.
• Excellent communication with both technical and business stakeholders.
• Dutch: professional working proficiency, spoken and written.
• English: professional working proficiency, spoken and written.
• Experience with Azure.
• Knowledge of IIS hosting.
• Experience with WCF.
• Experience with workflow or integration platforms.
• Knowledge of ETL processes or job scheduling solutions.
• Experience with performance optimization.
• Knowledge of secure software development practices.
• You understand technical complexity quickly.
• You work independently.
• You take ownership and responsibility.
• You are confident in challenging technical decisions constructively.
• You manage stakeholders well.
• You stay pragmatic without giving up quality.
• You enjoy bridging the gap between business and IT.

Conditions

Hybrid working, with 3 days onsite.

Full-time engagement.

Freelance contract.

Long-term assignment with stable future prospects.

Short-term start possible.

Location: Flemish Brabant / Brussels Region.