Top Senior C# Jobs in Washington, DC

Develop, design, code, and test software solutions for the Tax practice using object-oriented principles. Apply ATDD and CI/CD, build microservices and API integrations, conduct code reviews and QA, collaborate with cross-functional teams, manage project planning, and engage clients to deliver tailored digital transformation solutions.

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.

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.

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.

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.

The Sailpoint Consultant will maintain and support SailPoint IIQ infrastructure, troubleshoot issues, develop scripts, and assist project teams with identity and access solutions.

Design and develop solutions using Power Apps and Power Automate. Lead design sessions, implement data models, and manage solution lifecycles. Mentor junior developers and ensure adherence to governance best practices.

Design, build, and maintain cloud-native full-stack applications and backend services that support investment risk analysis. Own end-to-end delivery, contribute to architecture, apply automated testing and CI/CD, collaborate with stakeholders, reduce technical debt, and ensure reliable, observable data and analytics for portfolio risk and simulations.

Senior full‑stack .NET engineer responsible for design through production of secure, scalable web applications. Work includes C#/.NET backend, WPF/WCF components, REST APIs, frontend JS/HTML/CSS, cloud migration, code reviews, testing, and performance/security analysis. Expected to lead architecture, collaborate with teams, and apply SOLID, OOP, and SOA principles.

Develop and maintain Ruby and Rails applications, write Bash scripts, troubleshoot performance and multithreading issues, optimize SQL/MySQL queries, administer Unix/Linux/Solaris servers, and collaborate in Agile teams. Participate in API and SOA development and use source control (SVN/Git).

Develop and maintain a Blazor Server-based document publishing platform: render XML to HTML, implement C#-driven UI behavior, JS interop for rich in-browser editing, ensure security and accessibility, contribute to Azure DevOps CI/CD, participate in code reviews, documentation, UAT, and coordinate with stakeholders to deliver production-ready features.

Design, build, and scale the Substantiation Platform for validating and reconciling financial data. Provide architectural leadership and mentor engineers.

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 the design and development of Windows desktop applications, focusing on architecture, accessibility, and best practices, ensuring quality and performance across releases.

Design and implement runtime protocols, formats, and systems to capture, serialize, stream, and replay interactive 3D content across engines and AI models. Own engine subsystems from low-level C++ runtime to high-level C# APIs, optimize for performance, determinism, and low-latency streaming, and build interfaces for AI systems to inspect and invoke engine capabilities.

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.

The role involves developing cross-platform API abstractions for the Unity Editor using modern C++. Responsibilities include maintaining codebases and collaborating with worldwide teams.

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.

Support and enhance a mission-critical Model-Driven Power Apps solution on Dynamics 365. Design and develop entities, forms, PCF controls, plugins, integrations, Power Automate workflows, and Power BI reports. Manage security, troubleshoot production issues, participate in Agile ceremonies, perform deployments, and collaborate with stakeholders to translate requirements into maintainable solutions.

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.

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, 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).