Senior .NET Developer

Location: Harrisburg, PA Position Type: Mostly Remote Hybrid Schedule: Mostly remote role, must come onsite to pick up equipment Contract Length: Ongoing Contract with Yearly Renewals Position Overview: The Senior Software Developer provides hands-on development support for enterprise application modernization, working across legacy ASP.NET MVC applications and modern .NET 8–based solutions. This role requires immediate productivity in complex, regulated environments while contributing to incremental, low-risk modernization initiatives. Duties: Design, develop, and maintain modern .NET 8 solutions using ASP.NET Core Web APIs and Blazor (Server and/or WebAssembly). Enhance and support legacy ASP.NET MVC applications built on .NET Framework 4.x. Build reusable Razor components, shared libraries, and scalable service layers. Develop responsive, accessible user interfaces compliant with ADA and WCAG standards. Ensure interoperability between new services and existing legacy systems. Collaborate within Agile/Scrum teams, participating in sprint planning, backlog refinement, and technical reviews. Partner with architects and senior technical staff on implementation and design decisions. Provide accurate effort estimates and meet contractual delivery commitments. Develop API-based and file-based integrations with internal systems and approved third-party services. Implement background processing using scheduled jobs, hosted services, and Windows or cloud-hosted services. Design, optimize, and maintain SQL Server schemas, queries, and stored procedures. Implement data access using Entity Framework 6 and Entity Framework Core. Ensure transactional integrity, auditing, and compliance with data retention requirements. Implement claims-based authentication and enforce role-, title-, and action-based authorization. Apply secure coding practices and properly handle sensitive and confidential data. Implement logging, monitoring, and diagnostics using Application Insights or equivalent tools. Required Skills: 8+ years of professional software development experience delivering enterprise applications. 5+ years of hands-on experience with ASP.NET MVC using .NET Framework 4.x. 3+ years of hands-on experience with ASP.NET Core and modern .NET (.NET 6+ / .NET 8). Experience developing in C# within layered or N-tier architectures. Experience designing and consuming RESTful APIs. Experience with SQL Server, including relational data modeling and query optimization. Experience using Entity Framework 6 and Entity Framework Core. Experience building Razor Views and Razor Components. Experience with HTML5, CSS3, JavaScript, and jQuery for legacy application support. Experience with Blazor. Demonstrated experience implementing claims-based authentication and fine-grained authorization models. Proven ability to deliver independently with minimal onboarding in complex codebases. Hands-on experience using Azure DevOps, Git, and Visual Studio 2022. Demonstrated success delivering outcomes in long-term contract engagements. Preferred Skills: Experience modernizing long-lived, enterprise-scale applications. Prior experience working in government or highly regulated environments. Hands-on exposure to Azure App Services and Azure SQL. Experience implementing or managing Azure API Management. Experience with workflow engines such as Elsa or equivalent platforms. Strong ability to ramp up quickly in domain-heavy, legacy-modern hybrid systems.