Top Senior C# Jobs in Washington, DC

Lead design, development, integration, and validation of complex ground-system software. Define software architecture, derive and trace software requirements, participate in system reviews, collaborate with hardware/network/test teams, and support customer-facing technical deliverables.

The Senior Software Developer will create and maintain software solutions for U.S. Navy weapon systems, ensuring quality and reliability through testing, code reviews, and collaboration with stakeholders.

Design, implement, and maintain C++ and Python software for cross-platform, distributed real-time systems. Contribute to system architecture, APIs/messaging (gRPC/REST/ZeroMQ), CI/CD, automated testing, and integration of third-party simulation and hardware. Debug threading/timing issues and improve development workflows.

Lead architecture and implementation of high-performance C++ and Python systems, integrate distributed systems and hardware/software, manage CI/CD pipelines, debug and optimize real-time multi-threaded systems, guide end-to-end integration and verification, mentor engineers, and evaluate new technologies to improve system performance.

Lead architecture and implementation of high-performance C++ and Python systems, integrate distributed systems and simulation tools, own CI/CD pipelines, debug real-time multi-threaded systems, mentor engineers, and drive end-to-end integration across simulation and operational platforms.

Lead architecture and implementation of high-performance C++ and Python systems, integrate distributed and real-time systems, own CI/CD and build tooling, debug multi-threaded systems, guide cross-team integration and mentor engineers, and evaluate new technologies to improve simulation and autonomy platforms.

Lead design and integration of high-performance C++ and Python systems across distributed, real-time environments. Own CI/CD, containerization, build tooling, messaging/APIs, and debugging. Drive end-to-end integration, mentor engineers, set technical direction, and evaluate technologies to improve system performance and stability in autonomy and simulation domains.

Design, develop, and field high-performance Ground Control Station and C2 software using C++/Qt/QML and QGroundControl. Lead architecture and technical direction, mentor engineers, define APIs/ICDs, debug integration/latency issues, support field tests, implement post-mission debrief tools, and ensure interoperability with C2 standards.

Design, develop, test, and maintain scalable Java applications for government and enterprise systems. Build and integrate APIs, contribute to architecture and documentation, ensure performance and security, support CI/CD deployments, troubleshoot production issues, and ensure compliance with government standards.

Design, build, test, and deploy cross-platform mobile apps (React Native/TypeScript) and backend APIs (.NET/C#). Own features end-to-end, collaborate with Product/QA/DevOps, troubleshoot production issues, and improve API performance, scalability, observability, CI/CD, and test automation. Use AI-assisted development tools responsibly.

The .Net Developer will build software applications, collaborate with team members, document technical specifications, and resolve software issues.

The .Net Developer will design, develop, and maintain software applications, lead initiatives, document requirements, and resolve software issues.

Develop and implement a modern web information portal using front-end technologies, ensuring compliance with UX and 508 standards. Collaborate with stakeholders and integrate systems while managing project timelines and quality.

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

The Oracle PL/SQL Developer will provide infrastructure and back-end support, perform application testing and installation, and support user community by resolving database issues and performing UNIX administration functions.

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

Senior .NET Full Stack Developer responsible for designing, developing, testing, and enhancing enterprise .NET applications, integrating third‑party components, optimizing C#/ASP.NET code, automating operational workflows, and supporting large‑scale data processing and analytics. Works with lead architects across the SDLC and conducts architecture reviews, code reviews, and knowledge transfer.

Design and maintain healthcare software integrations, ensuring data flow between Epic EHR and systems while mentoring developers and ensuring quality standards.

Lead design and implementation of automated test frameworks and V&V for web, API, data, and backend systems. Integrate testing into CI/CD, support audit readiness and compliance (ASME NQA-1), manage defects and root-cause analysis, and drive quality metrics, documentation, and continuous improvement across engineering teams in a regulated nuclear environment.

Design, build, and lead development of scalable, secure, high-performance cloud ingestion systems handling large throughput uploads. Provide technical leadership, system design, architecture reviews, mentorship, cross-team collaboration, roadmap management, and process improvements across multi-cloud infrastructure.

Lead the design and development of Windows desktop applications, ensuring performance, accessibility, and collaboration with various teams. Oversee the entire feature lifecycle and address complex issues in a user-centric manner.

Design, build, and operate end-to-end backend services, APIs, and web applications. Own features from design through production, maintain integrations, improve CI/CD and observability, troubleshoot full-stack incidents, participate in on-call rotation, and raise engineering standards.

Lead design, development, enhancement, and maintenance of enterprise geospatial applications and APIs. Implement ArcGIS Enterprise solutions, web GIS apps, dashboards, integrations, and ensure compliance with federal IT, cybersecurity, and privacy requirements while guiding development teams and supporting testing, deployment, and O&M.

Responsible for architecting solutions that align with CMS needs, managing complex programs, and mentoring future technologists while adhering to federal standards.

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.