Senior Software Engineer II - .Net

About

Optum is a global organization that delivers care, aided by technology to help millions of people live healthier lives. The work you do with our team will directly improve health outcomes by connecting people with the care, pharmacy benefits, data and resources they need to feel their best. Here, you will find a culture guided by inclusion, talented peers, comprehensive benefits and career development opportunities. Come make an impact on the communities we serve as you help us advance health optimization on a global scale. Join us to start Caring. Connecting. Growing together.

At UnitedHealth Group, our mission is to help people live healthier lives and make the health system work better for everyone. We believe everyone—of every race, gender, sexuality, age, location and income—deserves the opportunity to live their healthiest life. Today, however, there are still far too many barriers to good health which are disproportionately experienced by people of color, historically marginalized groups and those with lower incomes. We are committed to mitigating our impact on the environment and enabling and delivering equitable care that addresses health disparities and improves health outcomes – an enterprise priority reflected in our mission.

The Senior Developer designs, builds, and supports scalable internal and external‑facing API solutions using the .NET technology stack. This role partners with product owners, users, and engineering peers to deliver secure, reliable, and maintainable software in an Agile environment, with solid focus on architecture, testing, performance, and production support.

Primary Responsibilities

• Design, develop, and maintain highly scalable internal and external‑facing APIs using .NET Core / ASP.NET Web API
• Collaborate with product owners and users to evaluate requirements by analyzing business needs, system workflows, data points, and integration boundaries with other enterprise applications
• Translate requirements into well‑structured technical designs, API contracts, and implementation plans with attention to scalability, performance, and maintainability
• Develop and maintain unit and integration tests for new features, and add tests to legacy code where necessary to reduce risk and improve coverage
• Ensure code, configurations, and deployments support scalability, resiliency, and operational readiness in production environments
• Support production users by monitoring services, investigating incidents, and resolving ticketed issues; provide root‑cause analysis and preventative fixes
• Perform code reviews and contribute to defining and enforcing coding standards, best practices, and consistent design patterns across the team
• Participate across the full development lifecycle—from concept and design through implementation, testing, deployment, and post‑release support
• Actively participate in Agile ceremonies (daily standups, planning, refinement, retrospectives) to communicate progress, risks, and dependencies
• Continuously improve technical skills by staying current with modern development tools, programming techniques, and engineering practices
• Comply with the terms and conditions of the employment contract, company policies and procedures, and any and all directives (such as, but not limited to, transfer and/or re‑assignment to different work locations, change in teams and/or work shifts, policies in regards to flexibility of work benefits and/or work environment, alternative work arrangements, and other decisions that may arise due to the changing business environment). The Company may adopt, vary or rescind these policies and directives in its absolute discretion and without any limitation (implied or otherwise) on its ability to do so

Required Qualifications

• Bachelor's degree in technical discipline (or equivalent practical experience)
• 8+ years of professional software development experience, with solid backend/API focus
• Experience working in an Agile environment using Scrum or Kanban
• Solid experience with database design and writing complex T‑SQL queries (SQL Server or equivalent)
• Demonstrated experience writing unit tests and integration tests and maintaining testable code
• Knowledge of modern web application and service design patterns such as Clean Architecture and/or Vertical Slice Architecture, event‑driven design, and asynchronous processing
• Solid understanding and hands‑on application of SOLID principles and clean coding practices
• Proven expertise with the .NET technology stack, including C#, ASP.NET MVC, and ASP.NET Web API / .NET Core
• Proven excellent communication skills with the ability to explain technical concepts to both technical and non‑technical audiences
• Proven self‑motivated, able to work with minimal direction, and able to manage multiple priorities effectively
• Proven solid analytical, problem‑solving, and critical thinking skills
• Ability to pass a strict background check due to work with sensitive data

Preferred Qualifications

• Experience with observability/monitoring tools and production support practices (alerting, dashboards, log analysis)
• Experience designing secure APIs (authentication/authorization, OWASP considerations, rate limiting, input validation)
• Familiarity with CI/CD pipelines and automated quality gates