Senior C# Developer

Loyal Source; Westford (MA); On-site; USD 94,000 - 131,000; Full time

Job summary

Loyal Source is seeking a Senior C# Developer to design, build, and maintain scalable, high-performance applications using .NET technologies. You will mentor junior developers and influence architectural decisions while delivering robust solutions with cross-functional teams.

The role emphasizes Windows application development, MSI installer packaging with WiX Toolset and Advanced Installer, and release engineering to ensure reliable installation, upgrade, and deployment processes.

Qualifications

• 5–6+ years of experience in software development using C#.
• “.NET Framework, .NET Core, Windows Services.”
• “Installer Technologies: Advanced Installer & WiX Toolset.”
• “Experience creating: MSI packages, Bootstrapper applications, Upgrade packages, Patches and hotfix installers & Silent installations.”
• “Knowledge of Windows Installer internals and troubleshooting installation issues.”
• “Release Engineering: building and managing CI/CD pipelines, GitHub Actions, PowerShell scripting”

Responsibilities

• Design, develop, test, and maintain applications using C# and .NET technologies.
• Create, maintain, and troubleshoot MSI installers using WiX Toolset and Advanced Installer.
• Design upgrade, patching, rollback, and migration strategies for software releases.
• Analyze and resolve production issues, and installation-related problems.
• Participate in code reviews and mentor junior developers.
• Work with QA teams to ensure software quality and release readiness.
• Contribute to CI/CD pipelines and release management processes.

Skills

C#

.NET Framework/.NET Core

Windows application development

WiX Toolset

Advanced Installer

CI/CD pipelines

GitHub Actions

PowerShell scripting

Release Engineering

Tools

WiX Toolset

Advanced Installer

Job description

About the Role

We are seeking a highly skilled Senior C# Developer to design, build, and maintain scalable, high-performance applications that support critical business functions. In this role, you will work closely with cross-functional teams to deliver robust solutions using modern .NET technologies, influence architectural decisions, and mentor junior developers. This is an opportunity to have a real impact on both technical strategy and product delivery.

The ideal candidate will have strong expertise in C#, .NET Framework/.NET Core, Windows application development, installer packaging using WiX Toolset and Advanced Installer, and experience with Release Engineering practices.

The candidate will work closely with development, QA, and product teams to deliver high-quality software releases while ensuring installation, upgrade, and deployment processes are reliable and scalable.

Pay Rate: $81 / hour

Key Responsibilities

• Design, develop, test, and maintain applications using C# and .NET technologies.
• Create, maintain, and troubleshoot MSI installers using WiX Toolset and Advanced Installer.
• Design upgrade, patching, rollback, and migration strategies for software releases.
• Analyze and resolve production issues, and installation-related problems.
• Participate in code reviews and mentor junior developers.
• Work with QA teams to ensure software quality and release readiness.
• Contribute to CI/CD pipelines and release management processes.

What We Look For

• 5–6+ years of experience in software development using C#
• .NET Framework, .NET Core, Windows Services
• Installer Technologies: Advanced Installer & WiX Toolset
• Experience creating: MSI packages, Bootstrapper applications, Upgrade packages, Patches and hotfix installers & Silent installations
• Knowledge of Windows Installer internals and troubleshooting installation issues
• Release Engineering: building and managing CI/CD pipelines, GitHub Actions, PowerShell scripting

Preferred Qualifications

• Experience with cloud platforms such as Azure or AWS
• Knowledge of microservices architecture, event-driven systems, or distributed systems
• Familiarity with frontend technologies (e.g., Angular, React, or Blazor)
• Experience with containerization (Docker, Kubernetes)
• Understanding of DevOps practices, infrastructure as code, and automated testing
• Previous experience leading technical initiatives or small development teams

About Loyal Source

Loyal Source provides healthcare and technology solutions designed to improve outcomes and support mission‑critical operations. Guided by innovation and purpose, we help organizations achieve success across complex challenges worldwide. Loyal Source is a military friendly employer and proud partner of the Military Spouse Employment Partnership program.

Loyal Source uses AI‑powered voice screening as part of our application process. After you apply, you will receive a brief qualification survey via text or email. Candidates who meet the position requirements will then be invited to complete a quick AI‑powered voice assessment. This easy, no‑scheduling‑required process helps us and the candidate move the hiring process forward faster.

We are committed to providing equal employment opportunities to all applicants. If you have a disability or medical condition and need a reasonable accommodation to participate in this step of the hiring process, you may request an alternative method or accommodation at any time by contacting Human Resources at [e-mail].

If you are a qualified individual with a disability or a disabled veteran, you may request a reasonable accommodation by contacting HR at [e-mail]. If you are unable or limited in your ability to access job openings or apply for a job on this site as a result of your disability, please select the accessibility menu to the (right or left) for more assistance. You can also request reasonable accommodations by contacting a telecommunications relay service by dialing 711 for direct access and assistance (tty).

This contractor and subcontractor abides by the requirements of 41 CFR 60-300.5(a) and 41 CFR 60-741.5(a).
These regulations prohibit discrimination against qualified individuals on the basis of protected veteran status or disability, and require affirmative action by covered prime contractors.