Senior Software Engineer (.NET)

Harmonia Holdings Group, LLC•McLean, VA

1d•Hybrid

About The Position

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.

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

Nice To Haves

Microsoft Azure certifications (preferred)
Experience with modern AI platforms and services, preferably within the Microsoft ecosystem (Azure AI, Azure OpenAI)

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