Senior Software Engineer

.NET / C# Developer – Legacy Application Support & ModernizationLocation: Fully RemoteEmployment Type: ContractPay Rate: $65/hour W2Position OverviewWe are seeking an experienced .NET / C# Developer to support, maintain, and enhance a portfolio of existing business applications primarily built on C# and .NET Framework 4.7, along with several older legacy applications.The immediate focus will be understanding the existing application environment, troubleshooting issues, making enhancements, and ensuring applications remain stable and reliable. Longer term, this developer will play an important role in modernizing the application portfolio and migrating legacy applications toward current versions of .NET and modern development standards.ResponsibilitiesSupport, maintain, troubleshoot, and enhance applications built primarily with C# and .NET Framework 4.7.Work within several older legacy applications and become comfortable navigating and improving existing codebases.Diagnose application issues, perform root-cause analysis, and implement reliable fixes.Develop enhancements and new functionality within existing applications based on business requirements.Review legacy code and identify opportunities to improve performance, maintainability, security, and reliability.Assist with developing a roadmap for upgrading and modernizing older .NET applications.Participate in the eventual migration of applications from .NET Framework to modern .NET.Refactor legacy code and replace outdated components, libraries, and development practices where appropriate.Work with application dependencies, integrations, APIs, databases, and supporting infrastructure.Test application changes and ensure upgrades do not negatively impact existing functionality.Document applications, technical dependencies, modernization recommendations, and development processes.Collaborate with internal technical and business teams in a fully remote environment.Required QualificationsStrong professional development experience with C# and .NET.Hands-on experience supporting applications built on .NET Framework 4.x, ideally .NET Framework 4.7.Experience working with legacy applications and existing/older codebases.Strong troubleshooting and debugging skills.Experience with ASP.NET and/or other Microsoft application development technologies.Experience working with SQL and relational databases.Ability to understand an unfamiliar application, trace existing code, and independently resolve issues.Experience maintaining production applications while implementing enhancements and improvements.Strong communication skills and ability to work independently in a remote environment.Preferred QualificationsPrevious experience modernizing or migrating legacy .NET Framework applications to newer versions of .NET.Experience with ASP.NET MVC, Web API, REST APIs, IIS, Entity Framework, or similar Microsoft technologies.Experience upgrading application dependencies, libraries, and frameworks.Familiarity with modern development practices including Git, CI/CD, automated testing, and code reviews.Experience developing modernization strategies for applications that cannot be upgraded all at once.Ideal CandidateThe ideal candidate is someone who is strong in C#/.NET but isn't afraid of legacy code. This person should be comfortable stepping into applications running on .NET Framework 4.7 and potentially older technologies, keeping them operational today while helping the organization determine the best path toward a more modern .NET environment.This is not strictly a greenfield development position. The successful candidate will have the patience and technical depth to understand existing applications, improve them, and gradually help move the environment toward the latest generation of Microsoft development technologies.The pay range for this position is 60 to 65hr W2. Benefits available to contract/temporary professionals include medical, vision, dental, and life and disability insurance. Hired contract/temporary professionals are also eligible to enroll in our company 401(k) plan. Visit roberthalf.gobenefits.net for more information. Our specialized recruiting professionals apply their expertise and utilize our proprietary AI to find you great job matches faster.