Top Senior .NET Developer Jobs in Washington, DC

Designs, develops, tests, deploys, and manages .NET full-stack applications supporting FBI IT infrastructure. Responsibilities include integrating third-party components, enhancing existing code, automating operations and maintenance, large-scale data processing, statistical modeling, advanced analytics, and full software development lifecycle participation. The role also conducts architecture reviews, milestone reviews, resource estimation, process improvement, quality assurance, and team mentoring.

Modernize legacy Java and .NET applications by analyzing dependencies, preserving APIs and business behavior, building compatibility adapters, refactoring services, and supporting migration, testing, deployment, cutover, and retirement. The role also requires secure DevSecOps practices, documentation, production troubleshooting, stakeholder communication, and protection of classified and Controlled Unclassified Information in government environments.

Develop and maintain full-stack web applications using .NET, ASP.NET, React, and related technologies. Design front-end and back-end components, write and test scalable code, troubleshoot issues, participate in code reviews, and collaborate with cross-functional teams throughout the software development lifecycle. The role is onsite at a government facility in Washington, D.C., and requires an active Top Secret clearance with SCI and CI Poly eligibility.

Develop and maintain full-stack web applications using .NET and React. Design front-end and back-end components, write scalable code, conduct testing, troubleshoot issues, participate in code reviews, and collaborate with cross-functional teams throughout the software development lifecycle. The role requires active TS/SCI clearance, U.S. citizenship, a bachelor’s degree, and at least eight years of experience.

Develop and maintain full-stack web applications using React, .NET, and related technologies. Design front-end and back-end components, write scalable code, conduct testing, troubleshoot issues, participate in code reviews, and support the full software development lifecycle. Collaborate with cross-functional teams and clients while applying secure coding, architectural patterns, cloud services, and DevOps practices. The role also includes mentoring, technical communication, and contributing to continuous process improvement.

Leads full-stack development, maintenance, troubleshooting, and implementation of a federal HR position classification application. Develops .NET APIs, integrates PeopleSoft and Oracle data, maintains authentication services, automated tests, documentation, and Azure DevOps pipelines. Builds AI-assisted applications using LLMs and related technologies while supporting production operations, root-cause analysis, and controlled releases.

Leads architecture and development of complex backend services for a commercial health plan platform. Designs .NET Core and Azure systems, develops claims, eligibility, and benefits functionality, manages healthcare data integrations, and owns cloud infrastructure and CI/CD architecture. Provides technical leadership through code reviews, testing standards, mentoring, and architecture decisions while ensuring performance, reliability, security, and regulatory compliance.

Develop and optimize Microsoft .NET applications, legacy systems, and microservices with a focus on performance, scalability, reliability, and observability. Responsibilities include code reviews, performance testing, CI/CD integration, architecture and sprint delivery, legacy code and SQL tuning, cloud application deployment on Azure, automated testing, and resolving customer issues. The developer collaborates with architects, QA, technical support, and cross-functional teams using SAFe Agile practices.

Design, develop, deploy, and support enterprise integration solutions using C#, .NET, Azure, APIs, microservices, middleware, and Azure Service Bus. Integrate SAP, Dynamics 365 CRM, IVR systems, databases, payment gateways, and traffic management platforms. Build secure, scalable, high-volume data exchanges, troubleshoot production issues, document technical solutions, and support implementation and post-go-live activities, including scheduled onsite work in Middletown, Pennsylvania.

Senior .NET Software Engineer responsible for end-to-end software development using Microsoft technologies. Requires extensive experience in SDLC, design principles, technical documentation, web application development with .NET, Agile/SCRUM, Entity Framework, database design, and version control. Familiarity with project tools JIRA, TEMPO, Bitbucket, and Confluence preferred.

Senior .NET Web App Developer responsible for designing and building .NET web applications, implementing Oracle PL/SQL solutions, using Entity Framework and Blazor, applying design principles, producing technical documentation, performing performance tuning, and collaborating in Scrum/Agile teams with Bitbucket, JIRA, Tempo, and Confluence.

Develop and maintain web-based applications using .NET/C#, JavaScript, HTML/CSS, SQL and Oracle/SQL Server. Perform root cause analysis, collaborate with teams for requirements, follow Agile SDLC, present change demonstrations, and use Azure DevOps/Jira for lifecycle management. Implement and maintain Blazor components.

Design, build, and maintain production-grade .NET web applications and APIs on Azure. Own full-stack delivery from data models and SQL to front-end components, CI/CD, testing, and architecture. Collaborate with product and delivery teams, participate in code reviews, and ensure secure, observable, well-tested services.

Develop and maintain C#/.NET applications throughout the software development lifecycle, including requirements analysis, architecture, coding, testing, debugging, integration, and configuration. Collaborate with clients and team members to prioritize development backlogs and plan releases. Build reliable, reusable code, analyze system requirements, and support applications using .NET technologies, SQL, APIs, JavaScript, and related systems.

Leads the design, development, and implementation of full-stack applications using C#, .NET, Angular, Azure, and SQL Server. Collaborates with cross-functional teams, ensures application security, performance, and scalability, applies Git-based version control practices, mentors developers, and stays current with emerging technologies.

The Principal Engineer will lead technical initiatives in AI-driven tax software, mentor engineers, enforce technical standards, and contribute to architectural design and product innovation.

Build and maintain scalable, cloud-native APIs and high-value core system components using .NET and related technologies. Lead software architecture and testing discussions, enhance core offerings, collaborate cross-functionally, and ensure quality through code reviews, unit testing, functional testing, telemetry, and performance tuning. Mentor teammates and contribute to continuous technical and process improvement.

Develop, test, deploy, maintain, and support enterprise software applications for a government customer. Responsibilities include designing application architectures, building front-end, business logic, REST API, and database components, creating Power BI reports, automating testing with Selenium, troubleshooting production issues, and assisting with deployments, configuration, upgrades, and documentation in an Agile Kanban environment.

Lead development of secure, scalable digital banking software across front-end and backend systems. Design Angular or React applications, build APIs, optimize SQL performance, integrate third-party platforms, improve code quality, implement testing strategies, and mentor engineers. Collaborate with cross-functional teams in an Agile environment while supporting cloud-native practices, regulatory compliance, and continuous product improvement.

Owns the design, development, testing, deployment, and maintenance of production software. Builds C#/.NET backend services, Angular web applications, and .NET MAUI mobile apps; optimizes SQL Server databases; resolves production issues; improves reliability, security, performance, and observability; writes tests and documentation; participates in code reviews; and translates ambiguous business needs into maintainable technical solutions.

Build scalable backend-heavy services and applications using C# and .NET, while contributing to Angular and TypeScript UI development. Design and develop REST APIs and microservices, work with relational databases, implement automated testing and CI/CD, and ensure system security, scalability, and performance. Preferred work includes event-driven architectures, messaging systems, NoSQL databases, caching, search technologies, and mentoring engineers or leading technical initiatives.

Develop, test, deploy, and maintain full-stack web applications using .NET and React. Design scalable front-end and back-end solutions, troubleshoot technical issues, participate in code reviews, and follow software development best practices. Collaborate with designers, product managers, and developers throughout the software lifecycle. The role requires onsite work in Washington, DC and an active Top Secret clearance.

The .Net Developer will support business functions by developing, implementing, and maintaining applications, collaborating in a Scrum Team, and ensuring software meets specifications.

The Sr. .NET Developer will support business functions by developing, implementing, and maintaining application systems, focusing on BI tools and Web APIs.

Develop, enhance, and maintain backend web applications and services using C#/.NET. Implement features with ASP.NET, Entity Framework, and SQL Server; write unit and integration tests; perform troubleshooting, code reviews, vulnerability remediation, and O&M tasks while collaborating with senior engineers and cross-functional teams.