Senior Software Engineer (.NET)

Harmonia Holdings Group, LLC is an award-winning, rapidly growing federal government contractor committed to providing innovative, high-performing solutions to our government clients and focused on fostering a workplace that encourages growth, initiative, creativity, and employee satisfaction.

Description

Title: Senior Software Engineer (.NET)

Location: Hybrid within McLean, VA

Terms: Full-time

Clearance: Public Trust Eligible

Position Description

We are seeking a Senior Software Engineer (.NET) that will be responsible for delivering high-quality, maintainable software across the full stack. You will work across backend services, web applications, and database layers while collaborating with cross-functional teams in an Agile environment.

This role requires strong technical depth, disciplined engineering practices, and the ability to troubleshoot complex issues across multiple tiers.

Responsibilities

• Design, develop, and maintain applications using C# and the .NET stack (MVC, .NET Core, Web API)
• Build and enhance web applications using ASP.NET Web Forms and modern front-end technologies (JavaScript, TypeScript, CSS/SASS, Bootstrap)
• Develop and optimize data access layers using Entity Framework, LINQ, and ADO.NET
• Write and tune SQL Server objects (T-SQL, stored procedures, UDFs, triggers)
• Support database architecture and participate in migration efforts
• Design and maintain service-oriented components (WCF)
• Implement unit testing using NUnit, MSTest, or similar frameworks
• Troubleshoot issues across application, database, and server layers
• Collaborate with development teams to deliver high-quality solutions
• Participate in Agile ceremonies and continuous improvement efforts

Requirements

• Bachelor’s degree in Computer Science or related field with 7+ years of experience
• Ability to obtain and maintain a Public Trust clearance; active public trust is preferred
• Strong experience with C# and the .NET ecosystem (.NET Core, MVC, Web API, WCF)
• Strong experience with SQL Server (including T-SQL and database design)
• Experience building and maintaining full-stack applications
• Hands-on experience with Azure DevOps, CI/CD pipelines, and release management

Knowledge, Skills, and Abilities

• Strong problem-solving ability across application, database, and infrastructure layers
• Ability to write clean, efficient, and testable code
• Experience working in Agile delivery environments
• Familiarity with static code analysis tools (e.g., SonarQube)
• Experience with modern AI platforms and services, preferably within the Microsoft ecosystem (Azure AI, Azure OpenAI)
• Excellent written and verbal communication skills with the ability to partake in oral presentations
• Microsoft Azure certifications (preferred)