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.

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

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.

Design, develop, and maintain ground control and mission-planning software for the X-BAT platform. Build full-stack, low-latency, fault-tolerant systems for telemetry fusion, operator UIs (React/TypeScript), communication interfaces, and integrations with autonomy and flight teams. Lead feature development, write well-tested code, and collaborate across embedded, UX, and flight-test teams to deliver field-ready solutions.

Build and evolve Unity’s PolySpatial core technology across low-level C++ and high-level C# systems. Design high-performance APIs for embedded, cross-process, and networked environments; manage execution timing and resource contention; and synchronize assets and components under bandwidth and latency constraints. Responsibilities include engine architecture, serialization, runtime performance, multithreading, networking, and end-to-end implementation and debugging.

Lead the design, development, testing, deployment, and maintenance of software applications. Collaborate with cross-functional teams, translate requirements into technical specifications, improve existing codebases, conduct peer reviews, and mentor junior developers. The role requires software development, programming, SQL databases, cloud services, CI/CD pipelines, DevOps practices, and Agile experience.

Own Ditto’s Rust SDK observability strategy and implementation across iOS, Android, desktop, and embedded platforms. Design telemetry, logging, tracing, support bundles, buffering, sampling, and export systems optimized for constrained devices and intermittent connectivity. Improve logging performance, maintain Rust SDK features, and support customers debugging production integrations. The role requires systems-level Rust, FFI, cross-platform SDK development, observability design, strong written communication, and customer empathy.

Leads Agile full-stack engineering teams through design, development, testing, deployment, and support. Guides architecture, code quality, mentoring, technical risk management, operational priorities, and cross-functional delivery. Develops secure enterprise applications using Java, Angular, .NET, AWS, Docker, EKS, databases, Kafka, and CI/CD tooling. Coordinates with federal stakeholders, vendors, cybersecurity, infrastructure, and identity teams while supporting change management, incident response, governance, and production troubleshooting.

Build and maintain scalable full-stack web applications using .NET, React, Next.js, and Azure. Responsibilities include feature delivery, API and microservices development, testing, code reviews, architecture, performance optimization, security, CI/CD support, cloud deployment, and production support. Senior engineers will mentor teammates and influence engineering standards, while early-career engineers receive mentorship and progressively greater ownership.

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.

Develop and architect enterprise Power Platform solutions using Power Apps, Power Automate, Dataverse, and Power BI. Responsibilities include data modeling, integrations, PCF development, Azure connectivity, governance, ALM, DevOps deployment, security, troubleshooting, documentation, stakeholder workshops, and mentoring. The role also involves designing user interfaces, conducting usability research, and creating dashboards. Work is onsite at a government facility in Washington, D.C.

Leads hands-on development of full-stack applications using .NET, React, Next.js, and Azure. Owns architecture, coding, code reviews, testing, security, reliability, observability, production support, and cloud deployment. Integrates AI and GenAI capabilities such as LLM features, RAG, semantic search, and agentic workflows. Mentors engineers, establishes technical standards, collaborates with stakeholders, supports hiring, and helps deliver scalable, secure software.

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.

Leads technical initiatives and designs, builds, operates, and improves scalable distributed systems. Collaborates across organizations, drives maintainability and performance, evaluates emerging technologies, delivers iterative releases, and mentors engineers. Requires polyglot full-stack development, strong SQL and distributed systems expertise, cloud experience, communication skills, and quarterly or as-needed travel. Preferred experience includes event-driven architectures, AI-assisted development, Kafka, APIs, containers, infrastructure as code, monitoring, CI/CD, and agile methodologies.

Develop and support applications using Oracle, SQL Server, MySQL, PostgreSQL, Node.js, TypeScript, and emerging cloud and AI technologies. Build database procedures, functions, packages, web service integrations, and application-to-database solutions. Collaborate with stakeholders and technical teams, incorporate user feedback, support multiple initiatives, and solve complex application development problems. The hybrid role supports DIA in Washington, D.C., requires TS/SCI clearance and willingness to take a CI polygraph.

Develop highly available, scalable cloud-based integration services for Axon’s real-time operations platform. Drive cross-team technical architecture, integration frameworks, partner onboarding, technical roadmaps, and reusable platform components. Collaborate with engineering, product, design, professional services, and external partners; lead architecture reviews, mentor engineers, improve engineering processes, and leverage AI to enhance customer experiences.

Serve as a customer-facing education domain advisor supporting Salesforce sales opportunities with higher education institutions. Partner with account executives and solution engineers, lead discovery workshops and architecture presentations, design business and technical architectures, contribute to RFPs, assess risks, and deliver educational content. Advise executive stakeholders on cloud transformation, Salesforce capabilities, Agentforce, integrations, security, and enterprise architecture while meeting performance objectives. The role includes approximately 25% travel.

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.

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.

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