Top .NET Developer Jobs in Philadelphia, PA

Design, build, and operate .NET backend services and APIs using C#/ASP.NET Core and EF Core/SQL. Author and iterate specification artifacts (OpenSpec), leverage AI coding assistants, implement automated tests, ship via CI/CD to the cloud, review peers' specs/code, mentor engineers, and collaborate with product, QA, and cross-functional teams to deliver production services.

Lead development and support of the FactorTrust Bureau platform across the full software lifecycle. Design and implement enterprise-scale .NET solutions, ensure security and compliance, drive cloud migration and DevOps practices, monitor performance, and manage incident/change processes while collaborating with global teams.

Lead development and support of enterprise insurance applications on the Microsoft .NET stack. Design, build, and maintain secure, scalable systems and integrations, troubleshoot production issues, modernize architecture and cloud adoption, and improve CI/CD and automated testing while collaborating with product, project, and business stakeholders.

Design, build, and maintain backend services and RESTful APIs using C# and ASP.NET Core; implement business logic, data access, authentication/authorization, and integrations with enterprise and third-party systems; write unit and integration tests; troubleshoot production issues; support mobile API integration, Azure deployment, and CI/CD in an Agile environment.

Develop and maintain enhancements for the M5 FleetFocus web application using C#, ASPX/ASP.NET, HTML5, XML, and JavaScript. Build and modify SQL statements and database objects in Oracle and SQL Server. Define C# interfaces for 3rd-party integrations, troubleshoot tickets, collaborate with PM/QA/support, and use Visual Studio 2013 and SVN for code changes.

The .NET Developer will engage in software development primarily using C#, ASP.NET, and SQL Server. Responsibilities include developing large applications and ensuring effective communication.

Lead design, development, and implementation of full-stack applications using .NET and Angular. Collaborate with teams to gather requirements, ensure security, scalability, and performance on Azure, manage SQL Server databases, use Git for version control, and mentor engineering teammates while adopting best practices and emerging technologies.

Lead development of maintainable .NET applications within a small team, apply test-driven development, coach client teams on modern software practices, and continuously improve technical skills.

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.

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 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.

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.

Contract remote .NET/Kentico web developer to build interactive, dynamic websites. Requires front-end web development experience and familiarity with the Kentico CMS. Six-week engagement.

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.

Hands-on lead developer/technical architect responsible for coding (.NET Core/.NET 8+), designing Azure-first architectures, building microservices and APIs, implementing Azure PaaS services and monitoring, performing code reviews and mentoring, troubleshooting production issues, and coordinating delivery with onshore/offshore teams.

Seeking a Senior .NET Developer with experience in Sitecore CMS and financial systems integration. Must have strong software development skills and experience with Agile methodologies.

The .Net Developer will work in agile teams, handling software development tasks including design, testing, and deployment while supporting existing applications.

The .NET FullStack Developer will design, code, test, and debug software product enhancements while ensuring high performance and maintainability, working closely with various teams.

Develop, maintain, and optimize backend services and RESTful APIs using Node.js, Java, or .NET. Integrate with databases and third-party services, collaborate with cross-functional teams, participate in code reviews, and ensure performance, reliability, and security in an Agile environment.

Lead design, implementation, and maintenance of the CoverGo SaaS platform across front-end and back-end. Provide technical direction, optimize performance and security, enforce coding standards, conduct code reviews, mentor junior developers, and collaborate with product and design teams to build scalable, high-traffic insurance enterprise solutions.

Develop, maintain, and modernize secure, scalable web applications using C#, ASP.NET Core, MVC, Razor Pages, and Web API. Implement secure coding (HIPAA/OWASP), optimized SQL Server database work, audit logging, and integrations. Collaborate with stakeholders, use Azure DevOps/Git for CI/CD and work tracking, and support migrations to cloud-enabled architectures.

The Back End Software Engineer will design and build scalable services for a SaaS platform, collaborate with teams, and contribute to quality code and architecture discussions.

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.

Expert-level full‑stack .NET engineer who designs, develops, tests, and supports secure, scalable enterprise applications. Leads large projects, authors technical specs, mentors engineers, enforces SDLC and security/audit requirements, participates in Agile/Scrum, and drives technical strategy and innovation. Availability for occasional travel and on-call support is required.