Senior .NET Developer

Koniag Government Services, LLC•Washington, DC

2d•$135,000 - $165,000•Hybrid

About The Position

Koniag Emerging Technologies, LLC, a Koniag Government Services company, is seeking a Senior .NET Developer with an active Secret security clearance to support the company and its government customer in Washington, DC. This is a hybrid position requiring one day onsite per week. The successful candidate will lead the design, development, and implementation of software solutions using .NET Framework, ASP.NET Web API, Angular, and Oracle, and will lead operations and maintenance of a Federal HR position classification application. The candidate will also support and lead new AI-assisted development as needed, including tools that analyze position descriptions and support classification decisions. The role includes maintaining and enhancing a full-stack application, developing enterprise APIs and integrations with PeopleSoft HR data, maintaining automated regression tests and technical documentation, and maintaining the Duende IdentityServer host and its OAuth 2.0 / OpenID Connect configuration. The position also involves designing and building AI-assisted applications in .NET.

Requirements

Active Secret security clearance; U.S. citizenship is required.
Bachelor's degree in Computer Science or a related field, or four additional years of experience in lieu of a degree.
At least seven years of total software development experience, including at least six years of .NET development.
Strong proficiency in C#, ASP.NET Web Forms, MVC, and Web API, and both .NET Framework and modern .NET.
Experience designing and building enterprise ASP.NET Web APIs secured with OAuth 2.0 / OpenID Connect.
Working knowledge of Oracle databases and SQL, including ODP.NET or Entity Framework with Oracle.
Demonstrated experience building or integrating AI features in applications, such as LLM APIs or agents.
Experience using GitHub Copilot or a similar AI coding assistant, and experience using AI for regression testing.
Experience using Azure DevOps for Git source control, build and release pipelines, and deployments.
Experience supporting production applications, including troubleshooting, root-cause analysis, and fixes under change control.
Familiarity with JavaScript, HTML, and CSS.
Strong problem-solving, communication, and interpersonal skills.

Nice To Haves

HR knowledge, especially federal HR, OPM position classification, GS grades, and position descriptions.
Experience with Duende IdentityServer, token-based authentication, and single sign-on.
Experience with Angular, including standalone components, reactive forms, and RxJS.
Experience building MCP servers, multi-agent systems, or Azure OpenAI / Microsoft AI solutions in .NET.
Experience performing automated testing with Playwright, xUnit, or similar tools.

Responsibilities

Maintain, enhance, and troubleshoot applications across the .NET Framework, ASP.NET Web API, Angular, and Oracle stack.
Develop and maintain enterprise ASP.NET Web APIs serving the classification application and related HR applications.
Support integration with PeopleSoft HR data, including organizational hierarchies, position data, and locality data.
Maintain automated regression tests, such as Playwright tests, and technical documentation for the application stack.
Prepare implementation guides and technical documentation.
Maintain and upgrade the Duende IdentityServer security token service host, including OAuth 2.0 / OpenID Connect clients, scopes, and certificates.
Design and build AI-assisted applications in .NET, including tools that analyze position descriptions and support classification determinations.
Lead the design, development, and implementation of software solutions and lead operations and maintenance of the Federal HR position classification application.
Support and lead new AI-assisted development as needed.