Top Senior C# Jobs in Washington, DC

Design, build, test, and maintain tax-focused software solutions using Java, Python, C# and JavaScript. Apply ATDD and CI/CD, create APIs and microservices, perform code reviews and debugging, manage project delivery, and collaborate with cross-functional teams to improve business processes and client outcomes.

Design and implement runtime protocols, formats, and systems to capture, serialize, stream, and replay interactive 3D content across engines. Own C++ runtime and C# APIs across editor, build, simulation, streaming, and playback. Optimize for low-latency, determinism, memory and bandwidth constraints, and build AI interfaces for inspecting and invoking engine state.

Lead design, build, and operation of large-scale, distributed, full-stack systems. Drive technical initiatives, deliver iterative customer-focused releases, improve maintainability and performance, mentor engineers, research and adopt new technologies, and collaborate across teams to meet enterprise needs.

As a Senior Software Engineer, you'll design architecture, mentor engineers, and drive the adoption of AI practices to enhance development workflows and system reliability.

Lead and deliver design, development, integration, testing, deployment, and sustainment of mission-critical NOAA Marine Operations software. Provide architecture and technical leadership across C#/.NET, JavaScript, databases, Windows and web environments; manage Agile delivery, testing, release, configuration, and troubleshooting; mentor developers and coordinate with cybersecurity, infrastructure, and operational stakeholders.

Design, develop, and review software as part of an Agile scrum team. Collaborate with architects, QA, analysts, and customers to build large-scale hosted applications, contribute to security and risk assessments, resolve operational issues, and participate in on-call support and deployments.

Participate in all SDLC phases on a scrum team to design, develop, test, and deploy large-scale healthcare applications. Collaborate with architects, QA, product and clinical analysts, contribute to security and risk assessments, interact with customers to resolve issues, and support on-call/operational needs.

The role involves designing, developing, and testing applications using .NET technologies, building APIs, and implementing AI/ML solutions. Responsibilities include contributing to architectural decisions and mentoring team members.

Lead architecture and design for highly available, low-latency cloud services. Drive AI-first engineering practices, evaluate and integrate AI-assisted development tools, mentor engineers, perform code and architecture reviews, and collaborate with Product and Design to build scalable, observable, and automated systems.

Design, develop, and implement Microsoft Power Platform solutions (Power Apps, Power Automate, Power BI, Dataverse) and UiPath RPA across all project phases. Provide technical SME support, architecture, integrations, end-user training, documentation, and production support. Lead demos, follow CoE/governance standards, collaborate with stakeholders, and ensure high-quality, secure deployments for clients.

Design, build, deploy, and operate backend services, APIs, integrations, and web applications. Own end-to-end features, improve CI/CD and observability, troubleshoot cross-service issues, participate on-call, and collaborate with product and leadership to deliver reliable production systems.

Develop and maintain cloud-based enterprise web applications using React, C#/.NET and/or Python. Build RESTful APIs, work with SQL Server/PostgreSQL, participate in CI/CD and Azure deployments, troubleshoot production issues, follow secure coding and accessibility standards, and collaborate on Agile teams.

Design, build, and lead enterprise Power Platform solutions (Power Apps, Power Automate, Dataverse, Power BI). Drive architecture, integrations, PCF and C# extensibility, DevOps/ALM, governance, stakeholder workshops, troubleshooting, and documentation while mentoring teams and shaping platform strategy for a federal client.

Lead technical design, development, modernization, and deployment of enterprise web applications on Azure Government and Microsoft 365. Mentor teams, enforce standards, implement CI/CD and DevSecOps, migrate legacy systems, develop Python/ASP.NET backends and React frontends, manage databases (SQL Server/PostgreSQL), and ensure security/compliance (FISMA, NIST, ATO).

As a Senior Software Engineer in Test Automation, you'll design automation frameworks, develop CI/CD pipelines, and ensure the quality of VR training products.

Design, develop, and deliver end-to-end full‑stack solutions using modern frameworks and languages. Work across front-end and back-end (UIs, middleware, services, APIs), collaborate on Agile Scrum teams, use SQL/NoSQL databases, and support production-ready systems. Must be able to obtain Public Trust vetting. Position in Atlanta, GA.

Design, build, test, and maintain full-stack web applications for a federal client using C#, .NET, ASP.NET, Entity Framework, SQL Server, and React. Develop secure, scalable backend APIs, responsive front-end interfaces, integrate third-party services, remediate vulnerabilities, participate in SDLC activities, and collaborate with clients and teammates on architecture, performance, and deployment.

Seeking a Senior IT Developer/Engineer with extensive experience in .NET technologies, Oracle databases and software development lifecycle, to lead design and coding efforts.

Lead design and implementation of modernized insurance underwriting and policy administration solutions. Drive cloud transformation, data-driven and secure architectures, improve risk selection and claims resolution, enhance customer experience through automation, mentor technical teams, manage client relationships, and oversee project lifecycle, budgets, and delivery quality.

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.

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.

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 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 design, development, testing, and delivery of backend-focused .NET Core systems. Mentor engineers, drive Agile ceremonies, own end-to-end projects, improve performance and reliability, provide 3rd-level support, and collaborate with stakeholders to implement APIs, databases, cloud, and containerized solutions.

Design, develop, and maintain Model-Driven Power Apps and integrations on Dynamics 365/Dataverse. Build PCF controls, plug-ins, Power Automate flows, and Power BI reports. Troubleshoot production issues, manage source control and releases in GitHub, implement security models, and collaborate with stakeholders in an Agile environment for secure, scalable enterprise solutions.