Senior .NET Developer (.NET Framework / .NET Core)

Fathom Management LLC•Austin, TX

1d•$120,000 - $140,000•Remote

About The Position

We are seeking an experienced Senior .NET Developer to support the Department of Veterans Affairs by developing and maintaining enterprise APIs within an Azure-based integration platform. This platform enables secure communication between CRM applications and backend databases through scalable, high-performance RESTful APIs. The successful candidate will design, develop, test, and support .NET Framework and future-state .NET Core APIs while collaborating with application developers, architects, and data teams to deliver secure, reliable integration services supporting critical VA business operations.

Requirements

Bachelor's degree in Computer Science, Information Technology, Software Engineering, or a related field.
Minimum 5 years of experience developing enterprise .NET applications and APIs.
Advanced experience with C#
Advanced experience with ASP.NET Web API
Advanced experience with .NET Framework
Advanced experience with .NET Core
Advanced experience with RESTful API Development
Experience implementing authentication and authorization using OAuth, JWT, or similar security frameworks.
Experience developing and deploying APIs through CI/CD pipelines.
Strong troubleshooting, debugging, and software testing skills.
Excellent communication and collaboration abilities.
U.S. Citizen Required
Must be able to meet VA security and suitability requirements

Nice To Haves

Experience with Microsoft Azure.
Experience using Azure API Management (APIM).
Experience supporting Azure cloud integration platforms.
Experience leveraging AI tools to accelerate software development and testing.
Experience supporting Department of Veterans Affairs or other Federal agencies.
Familiarity with Agile software development methodologies.

Responsibilities

Design, develop, and maintain enterprise REST APIs using C#, ASP.NET Web API, .NET Framework, and .NET Core.
Develop scalable, secure, and maintainable integration services supporting enterprise applications.
Build APIs that integrate with authentication providers using OAuth, JWT, and modern security patterns.
Package and deploy APIs into Azure environments.
Publish and manage APIs using Azure API Management (APIM), including routing, versioning, monitoring, and policy enforcement.
Support cloud-based API modernization initiatives and future migration from .NET Framework to .NET Core.
Develop unit, integration, and functional tests for enterprise APIs.
Participate in code reviews and technical design sessions.
Leverage AI-assisted development and testing tools to improve software quality and productivity.
Troubleshoot and resolve production issues affecting enterprise APIs.
Deploy applications through automated CI/CD pipelines.
Collaborate with frontend developers, backend database teams, DevOps engineers, QA analysts, and solution architects.
Create and maintain technical documentation, API specifications, and implementation guides.