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)

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Here at Harmonia we are pleased to have been repeatedly recognized for our outstanding work culture, the innovative work we do, and the employees on our team who make a difference each day.  Some of these recognitions include:  

• Recognized as a Top 20 "Best Place to Work in Virginia"
• Recipient of Department of Labor's HireVets Gold Medallion
• Great Place to Work Certification for five years running
• A Virginia Chamber of Commerce Fantastic 50 company
• A Northern Virginia Technology Council Tech 100 company 
• Inc. 5000 list of fastest growing companies for eleven years
• Two-time SBA SBIR Tibbett's Award winner
• Virginia Values Veterans (V3) Certification

We recognize that every bit of our success is the result of our teams of hard-working, motivated, and innovative professionals who are proud to call themselves part of the Harmonia family!   In addition to competitive compensation, a family-focused culture, and a dynamic, productive work environment, we offer all full-time employees a variety of benefits including, but not limited to

• Traditional and HSA- eligible medical insurance plans 
• 100% employer-paid dental and vision insurance options 
• 100% employer-sponsored STD, LTD, and life insurance
• 5% 401(k) company matching
• Flexible-schedules and teleworking options
• Paid holidays and PTO Accrual Plans
• Paid Parental Leave
• Professional development and career growth opportunities 
• Team and company-wide events, recognition, and appreciation-- and so