.NET Developer

NET Developer North Charleston, SC (Onsite)We are seeking an experienced .NET Developer to support a federal program operating within a legacy technology environment while supporting ongoing system enhancements and integration efforts. This role focuses on maintaining, enhancing, and stabilizing existing systems while contributing to incremental improvements in system architecture, data integration, and development processes. The ideal candidate will have strong experience in .NET/C# development, familiarity with legacy systems, and a demonstrated ability to support data movement and integration across multiple platforms. This role will also contribute to improving development and deployment workflows, including supporting environment setup and system interoperability.ResponsibilitiesSupport development and maintenance of.NET/C# applications within a legacy system environment using Microsoft Visual Studio.Assist with establishing and stabilizing development and production environments, including coordination with stakeholders to address setup, configuration, and deployment challenges.Design and implement data movement and integration solutions across diverse platforms (legacy systems, databases, and modern tools).Analyze existing systems (including COBOL or mainframe components) and recommend practical enhancements to improve performance, reliability, and maintainability.Support data modeling and ETL processes to ensure consistent and reliable data flow.Collaborate with federal staff, vendors, and internal teams to support continuity of operations and technical alignment.Contribute to system and network architecture discussions, including connectivity and performance considerations.Support evaluation and application of modern tools and technologies, where appropriate, to enhance data processing and analytics capabilities.Identify opportunities to improve efficiency and scalability within existing system constraints.Assist with documentation, knowledge transfer, and system continuity efforts.Education and ExperienceBachelor's degree in Computer Science, Information Systems, Engineering, or equivalent experience.5–8+ years of experience in software development and/or system architecture.Required QualificationsStrong experience with: .NET Framework /.NET CoreC# developmentMicrosoft Visual Studio development environmentsOracle and/or Microsoft SQL Server (MS SQL)Experience with data integration, data movement, or ETL processes.Familiarity with legacy systems, including COBOL or mainframe environments.Experience troubleshooting and supporting development and deployment environments.Understanding of system integration and distributed systems.Strong communication and collaboration skills.Preferred QualificationsExperience working in federal or highly regulated environments.Familiarity with modern data platforms, including Databricks or similar technologies (desired for future-state capabilities).Experience with data modeling and database design.Exposure to cloud platforms (Azure, AWS, or similar).Basic understanding of network architecture and system connectivity.Exposure to AI/ML or advanced analytics tools.Certifications (Preferred)CompTIA Security+ (or equivalent baseline certification)CompTIA Network+Microsoft Certified: Azure Fundamentals or Azure Solutions ArchitectDatabricks Data Engineer Certification (desired)ITIL Foundation CertificationKey AttributesStrong problem-solving mindset in bridging legacy and modern systems.Practical, detail-oriented approach to system stability and incremental improvement.Ability to work effectively in structured environments with evolving requirements.Collaborative approach across government, contractor, and vendor teams.Commitment to documentation, knowledge sharing, and operational continuity.Security ClearanceActive Top Secret clearance. Able to obtain TS/SCI.Marathon TS is committed to the development of a creative, diverse and inclusive work environment. In order to provide equal employment and advancement opportunities to all individuals, employment decisions at Marathon TS will be based on merit, qualifications, and abilities. Marathon TS does not discriminate against any person because of race, color, creed, religion, sex, national origin, disability, age or any other characteristic protected by law (referred to as "protected status").