Freelance Sr. .NET Application Maintenance Engineer (AWS)

Location: Utrecht

Duration: 6 months (+ extension)

Contract Role | Immediate Start Preferred

We’re looking for a contract Senior .NET Engineer (AWS) 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 and are ready to hit the ground running, we’d love to hear from you.

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

Miguel Gomes