Top Senior .NET Developer Jobs in Washington, DC

The Senior .NET Developer will modernize applications, enhance legacy systems, lead Agile activities, and mentor junior developers while utilizing backend technologies.

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.

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.

Design, develop, test, and manage full-stack .NET applications; integrate third-party components; improve and automate operations; support large-scale data processing, statistical modeling, and advanced analytics; participate in all SDLC phases; conduct architecture reviews and knowledge transfer.

Design, build, and maintain production-grade .NET web applications and APIs on Azure. Own full-stack delivery from data models and SQL to front-end components, CI/CD, testing, and architecture. Collaborate with product and delivery teams, participate in code reviews, and ensure secure, observable, well-tested services.

Seeking a Senior Full Stack .NET Developer to work on a social good project, with strong skills in C#, AngularJS, design, and UX. Requires 5+ years of experience.

The Staff Engineer will leverage 5+ years of experience in C#, JavaScript, and frameworks to lead and innovate solutions in a collaborative environment.

Own production reliability for customer-facing radar and weather data services across Azure, colocation, and edge Kubernetes. Refactor C#/.NET services for multi-replica safety, design multi-cluster HA, operate self-managed Kubernetes, improve observability and automation, lead incident response and postmortems, and drive operational excellence and capacity planning.

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.

The Senior SharePoint .Net Developer will design, develop, and maintain SharePoint environments, troubleshoot production issues, and lead application development teams.

Senior .NET full-stack developer responsible for custom application development, API integrations, database optimization, deployments, troubleshooting, performance, security, and production support using .NET/C#, ASP.NET Core, SQL, modern frontend frameworks, cloud, and CI/CD.

Provide technical leadership to design, modernize, and sustain a portfolio of .NET web applications and Azure infrastructure. Develop and migrate WebForms to ASP.NET Core and SSRS to Power BI, maintain SQL Server databases, enforce secure coding and ATO compliance, ensure accessibility (Section 508/WCAG), and mentor junior developers while coordinating with VA stakeholders.

Design, build, and maintain scalable web applications for payroll and accounting. Collaborate with engineers and product partners, write tested code, participate in code reviews, contribute to architecture, improve CI/CD and monitoring, support production (including on-call), and communicate progress while continuously learning.

Design, develop, test, and deploy .NET solutions (APIs and web apps). Build and consume RESTful services, work with SQL and NoSQL databases, use cloud (Azure/AWS) and Docker, apply unit/integration/performance testing, participate in code reviews, define features via spikes, and architect scalable, high-performance systems. Support occasional after-hours and on-call rotation.

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

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.

Lead architecture and hands-on development for a core SaaS product suite (50% coding). Own technical roadmap, drive DevSecOps/IaC/TDD adoption, mentor teams, resolve performance and reliability issues, and translate product needs into scalable designs.

Develop and maintain web-based applications using .NET/C#, JavaScript, HTML/CSS, SQL and Oracle/SQL Server. Perform root cause analysis, collaborate with teams for requirements, follow Agile SDLC, present change demonstrations, and use Azure DevOps/Jira for lifecycle management. Implement and maintain Blazor components.

Senior .NET Software Engineer responsible for end-to-end software development using Microsoft technologies. Requires extensive experience in SDLC, design principles, technical documentation, web application development with .NET, Agile/SCRUM, Entity Framework, database design, and version control. Familiarity with project tools JIRA, TEMPO, Bitbucket, and Confluence preferred.

Senior .NET Web App Developer responsible for designing and building .NET web applications, implementing Oracle PL/SQL solutions, using Entity Framework and Blazor, applying design principles, producing technical documentation, performing performance tuning, and collaborating in Scrum/Agile teams with Bitbucket, JIRA, Tempo, and Confluence.

The Senior .NET Developer will work on developing and maintaining applications, mentor junior developers, and ensure compliance with regulations. The role requires expertise in full-stack development, particularly with SQL Server databases and Azure.

The Senior .Net Developer will enhance SDG's C#/.NET Core codebase, design high-load services, and optimize MS SQL queries, benefiting from a remote work environment and attractive benefits.

As a Senior Software Engineer at PerfectServe, you'll design, build, and maintain high-quality code for healthcare communication systems, mentoring junior engineers and collaborating across teams to improve patient care and clinical workflows.

Lead backend development on the scheduling platform modernization, contribute across products, write APIs, and drive AI-accelerated software development workflows.