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.

Senior Dynamics 365 developer to enhance and maintain a Model-Driven Power Apps solution. Responsibilities include customizations, PCF control development, plug-ins, integrations, Power Automate workflows, Dataverse configuration, Power BI reporting, security management, troubleshooting, and supporting Agile delivery and deployments.

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.

Designs and implements complex multi-cloud and hybrid environments, cloud modernization strategies, DevOps pipelines, infrastructure automation, CI/CD, and SRE practices. Leads client cloud migrations, transformations, security initiatives, and scalable architecture implementations across AWS, Azure, and GCP. Advises clients, manages consultant and engineering squads, oversees deliverable quality, supports proposals, develops accelerators, and collaborates across regions and practices.

As a Staff Software Engineer, you will lead technical strategies, develop APIs and microservices, and mentor engineers for innovation at GEICO.

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 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 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.

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

Performs ETL, backend database, data warehouse, and data pipeline testing. Develops Python- and SQL-based automation frameworks, validates data transformations and quality across AWS and Databricks platforms, and executes integration, regression, performance, and reconciliation testing. Creates test plans, analyzes defects, supports Agile Scrum teams, and collaborates with developers, data engineers, and business analysts to deliver reliable enterprise data solutions.

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 .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.

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.

Develop Temporal workflows and Go services to automate cloud operations, build reliable SRE platforms, participate in on-call/incident response, debug distributed systems, and enable self-service through documentation and CI/CD automation.

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.

Develop and support an ETRM front-office system for multiple commodities. Create POCs, design documents, integrations with third-party trading platforms, and collaborate with trading, risk, operations, and accounting. Implement scalable Java web applications, manage app servers, CI/build tools, and participate in Agile practices including pair programming and automated testing.

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

Lead .NET Core microservices architecture and backend quality, direct an offshore backend pod, design Azure SQL cache and REST APIs, implement Service Bus integrations, own CI/CD security gating, run demos, triage defects, and conduct client handoffs.

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.

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.

Provide O&M and development support for a production .NET web application. Gather and analyze requirements, design solution architecture, build and upgrade full-stack features, improve performance, and support the application lifecycle while collaborating with government and contractor teams.