Freelance .NET Application Maintenance Engineer (AWS)

Location: Utrecht

Duration: 6 months (+ extension)

Contract Role | Immediate Start Preferred

We’re looking for a .NET Engineer with proven experience in maintaining complex systems and a strong background in AWS and DevOps practices. This is a maintenance-heavy role where your expertise will ensure system stability, performance, and continuous improvement of both applications and cloud infrastructure.

What You’ll Be Doing:

• Maintain and enhance business-critical applications built with ASP.NET, .NET Core, and .NET Framework.
• Diagnose and resolve complex issues in production environments.
• Optimize MSSQL performance with advanced query tuning and stored procedure improvements.
• Work hands-on with a broad range of AWS services – beyond EC2, S3, and RDS – such as Lambda, ECS/EKS, API Gateway, IAM, CloudWatch, and more.
• Contribute to and improve DevOps workflows, CI/CD pipelines, and infrastructure-as-code (e.g., Terraform, CloudFormation).
• Monitor application and infrastructure health using AWS-native tools and logging frameworks.
• Communicate clearly with technical teams and stakeholders, providing updates on system performance and ongoing work.

What You Bring:

• Strong .NET background with experience in C#, ASP.NET, .NET Core, and legacy .NET Framework.
• Extensive experience with MSSQL, including stored procedures and performance tuning.
• Solid hands-on experience with a variety of AWS services, particularly in a DevOps or production support context.
• Familiarity with CI/CD tools like Jenkins, GitHub Actions, AWS CodePipeline, or similar.
• Experience with infrastructure automation using Terraform or CloudFormation.
• A proactive, problem-solving mindset and ability to work independently in a contract setting.

This is an opportunity to join a forward-thinking engineering team and make a direct impact on the reliability and performance of core systems. If you’re a .NET contractor with deep AWS expertise, we’d love to hear from you.

Darwin Recruitment is acting as an Employment Business in relation to this vacancy.

Eszter Hlavati