Senior .NET Modernization Developer
Job OverviewThe Senior Software Developer (Contractor) will provide hands-on development services supporting a modernization initiative, working on modern .NET 8/10 Blazor and MVC based solutions. This is a delivery-oriented role requiring contractors who can be immediately productive in existing enterprise codebases while contributing to incremental, low-risk modernization efforts in a regulated government environment.Scope of ServicesModern Application DevelopmentDevelop .NET 8/10 solutions using ASP.NET Core Web APIs and Blazor (Server and/or WebAssembly).Maintain and Enhance .NET 8/10 solutions using ASP.NET Core Web APIs and MVC.Build reusable Razor components and shared libraries.Implement responsive, accessible user interfaces compliant with ADA / WCAG standards.Ensure new services can be safely consumed by both new and legacy systems.Collaboration & DeliveryWork within Agile/Scrum teams.Participate in sprint planning, backlog refinement, and technical reviews.Collaborate closely with architects and senior technical staff on implementation decisions.Provide accurate estimates and meet contractual delivery commitments.Integration & Background ProcessingDevelop integrations with internal enterprise systems and approved third-party services.Implement API-based and file-based integrations.Develop background processing using:Scheduled jobsHosted servicesAzure-hosted Worker Services (Docker)Data & PersistenceImplement data access using Entity Framework Core.Design and optimize SQL Server schemas, queries, and stored procedures.Ensure transactional integrity, auditing, and compliance with data retention rules.Security & ComplianceImplement claims-based authentication and authorization.Enforce role-, title-, and action-based access controls.Follow secure coding standards appropriate for government-regulated systems.Properly handle sensitive and confidential data (PII, investigative information).Collaboration & DeliveryWork within Agile/Scrum teams.Participate in sprint planning, backlog refinement, and technical reviews.Collaborate closely with architects and senior technical staff on implementation decisions.Provide accurate estimates and meet contractual delivery commitments.Required Technical ExpertiseCore PlatformsC#ASP.NET Core MVCASP.NET Core / .NET 8/10Blazor (Server and/or WebAssembly)Front-EndRazor Views and Razor ComponentsHTML5 / CSS3JavaScript and jQuery (required for MVC applications)Responsive design principlesADA / accessibility complianceData & ORMSQL ServerEntity Framework CoreRelational data modeling and query optimizationArchitecture & PatternsLayered / N-Tier architectureRepository and Specification patternsDependency InjectionRESTful API designExperience bridging legacy applications and modern servicesIntegration & ToolingREST and file-based system integrationsBackground jobs and schedulersAzure DevOps (Repos, Pipelines, Boards)GitVisual Studio 2022/2026Application logging and diagnostics (Application Insights or equivalent)Docker DesktopPreferred Contractor QualificationsExperience modernizing long-lived enterprise systemsPrior government or regulated-industry experienceAzure App Services and Azure SQL exposureAzure API Management experienceElsa Workflows or equivalentAbility to ramp up quickly in complex, domain-heavy codebasesExperience Requirements8+ years professional software development experience5+ years ASP.NET Core / modern .NETDemonstrated success in long-term contract engagementsProven ability to deliver with minimal onboarding