Senior .NET Enterprise App Engineer

Clark Construction Group, LLC; United States; On-site; USD 65,000 - 170,000; Full time

Job summary

Clark Construction Group, LLC is seeking a Senior Application Developer to own and modernize a mission-critical Microsoft stack environment. You will ensure stability, lead development, and collaborate with IT leadership and vendors while balancing immediate support with long-term improvements.

Based in McLean, VA, this onsite role requires hands-on coding in C#, .NET, SQL Server, and REST APIs, with a focus on modernizing legacy systems, implementing CI/CD, and guiding technical decisions.

Qualifications

• Bachelor’s degree in Computer Science, Software Engineering, Information Systems, or related field.
• 6+ years of experience developing and supporting Microsoft ecosystem (C#, VB.NET, SQL Server).
• Strong experience with .NET Framework applications (WebForms, MVC, WCF).
• Proficient with HTML, CSS, JavaScript; solid SQL Server skills and T‑SQL.

Responsibilities

• Serve as the primary technical owner for internally developed web applications on the Microsoft stack.
• Maintain, troubleshoot, and enhance legacy applications for stability and performance.
• Analyze and reverse‑engineer existing systems to understand business logic and data structures.
• Design and implement improvements to architecture, code, and database design.
• Write, refactor, and optimize T‑SQL queries, stored procedures, and objects in SQL Server.
• Support and manage IIS-hosted applications, including deployment and security updates.
• Develop new functionality using C#, .NET, JavaScript, and related technologies.
• Build RESTful APIs to enable integration between legacy systems and modern apps.
• Contribute to modernization decisions including upgrades, refactoring, or cloud migration.
• Establish modern development practices: source control, automated builds, testing, deployment.
• Collaborate with stakeholders to translate workflows into technical solutions.
• Document system behavior, architecture, and dependencies for long-term support.

Skills

C#

VB.NET

SQL Server

.NET Framework

WebForms

MVC

WCF

HTML

CSS

JavaScript

IIS

Troubleshooting

Education

Bachelor’s degree in Computer Science / Software Engineering / Information Systems

Tools

Git

Azure DevOps

CI/CD pipelines

Job description

Clark Construction Group, LLC is seeking a Senior Application Developer to own and modernize a mission-critical Microsoft stack environment. You will ensure stability, lead development, and collaborate with IT leadership and vendors while balancing immediate support with long-term improvements.

Based in McLean, VA, this onsite role requires hands-on coding in C#, .NET, SQL Server, and REST APIs, with a focus on modernizing legacy systems, implementing CI/CD, and guiding technical decisions.