Software Engineer (.NET)

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