Software Systems Engineer

Sr. Software Systems Engineer (C#/.NET Developer)

Marathon is searching for a motivated, career and customer-oriented Sr. Software Engineer (C#/.NET Developer) who will work across EDI transaction processing, backend API development, and cloud native systems on AWS. This is a hands-on engineering role with direct impact on how VA healthcare data flows through our platform. This is a 100% Remote role.

JOB DESCRIPTION

• Design, build, and maintain C#/.NET/AWS backend services handling high-volume healthcare EDI transactions (837, 835, etc.)
• Parse, validate, and transform X12 EDI documents
• Debug complex transaction-level issues across payers, clearinghouses, and trading partners
• Write, optimize, and troubleshoot SQL stored procedures including performance tuning, query analysis, and complex data transformations
• Work with XML object store data: query, parse, and manipulate structured XML within MSSQL
• Write clean, testable, well-documented code and participate actively in code review
• Contribute to shared platform libraries and services used across multiple product initiatives
• Performs technical planning, high level and detailed requirements definition, test planning and execution with team members and stakeholders on a daily basis
• Serve as an active member of the software development team participating in daily stand-ups
• Deploy, support and ensure the performance, quality, and responsiveness of application
• Provide development support, as needed, for solutions deployed to production
• Implement long term solutions and building blocks within the agile framework for improved reusability
• Apply and promote best software engineering practices
• Use Integrated Development Environment (IDE) tools to include Visual Studio and Git

Education

• Bachelor's or master's degree in computer science, electronics engineering or other engineering or technical discipline is required.

Experience

• Minimum of 8 years of experience in software development using C#/.NET technologies
• Proven track record of working on complex software projects and leading development initiatives
• Experience with designing, developing, and deploying enterprise-level applications

Requirements

• Strong proficiency in C#/.NET ecosystem
• Proficiency in developing back-end applications using design and integration patterns
• Hands-on AWS experience (serverless, messaging, storage, databases) preferred
• Strong SQL skills: writing and optimizing stored procedures, troubleshooting execution plans, performance tuning in MSSQL
• Proficient with Git and GitHub
• Experience with MSSQL or similar relational databases
• Proficiency in database design and development, including working with SQL Server and Entity Framework.
• Familiarity with cloud platforms (e.g., Microsoft Azure, AWS) and services.
• Understanding of continuous integration/continuous deployment (CI/CD) practices and tools (e.g., AWS CodePipeline, CodeBuild, CodeDeploy).
• Knowledge of unit testing frameworks and tools (e.g., NUnit, xUnit, MSTest). - Proficiency in using development tools like Visual Studio and Visual Studio Code.
• Excellent problem-solving and analytical skills.
• Strong communication and interpersonal abilities.
• Ability to work independently and as part of a large team.
• Attention to detail and commitment to producing high-quality software.
• Ability to prioritize tasks and manage time effectively using JIRA.
• Experience with agile development methodologies (e.g., Scrum, Kanban).
• Familiarity with DevOps practices and infrastructure as code (IaC).
• Ability to conduct code reviews and provide constructive feedback.
• Experience with performance tuning and optimization of applications.
• Knowledge of microservices and event-driven architecture and containerization technologies (e.g., Docker, ECS, EKS) is a plus.
• Experience with healthcare payer/PBM systems, clearinghouses, or pharmacy operations is a plus

Clearance Requirement:

• US Citizenship with the ability to obtain and maintain a Public Trust clearance