OneMain Financial Jobs

Job#: 3017088

Job Description:

Job Title: Software Design Engineer 4

Duration: Approximately 5 months

Location: Onsite -- Greater Seattle Area, WA

Openings: 4

Shortlist Deadline: 1/9/2026

Rate Range: $73--$77/hr

Top 3 Must-Have Skills

1) C# / .NET Development (6+ years)

• Strong, hands-on experience developing production systems using C# across .NET Framework and modern .NET (.NET Core / .NET 6+).
• Proven experience working on large or legacy codebases, including refactoring, modernizing projects, and improving code quality.
• Experience with SDK-style project migrations, NuGet package upgrades, and .NET runtime/framework upgrades.
• Ability to write maintainable, testable code and troubleshoot complex issues in service-oriented systems.

2) Cloud Services (4+ years)

• Hands-on experience building, deploying, and operating services in a cloud environment.
• Experience developing and maintaining RESTful Web APIs hosted in the cloud.
• Practical experience with cloud environments, including subscriptions, resource groups, and service configuration.
• Familiarity with cloud-based CI/CD workflows and platform upgrades impacting live services.

3) Infrastructure as Code & DevOps Foundations (3+ years)

• Strong experience defining and maintaining infrastructure using Infrastructure as Code (IaC) tools (e.g., ARM templates, Bicep, or Terraform).
• Experience upgrading or migrating build and deployment pipelines (Azure DevOps or equivalent).
• Understanding of infrastructure modernization efforts such as pipeline migrations, environment isolation, and platform compliance requirements.
• Proven ability to improve developer productivity by strengthening build reliability, test pipelines, and automation.

Typical Day in the Role

• Design, develop, implement, test, and maintain business and computer applications software or specialized utility programs.
• Work on modernization of services, code base, and infrastructure, focusing on tasks related to business logic.
• Specific tasks include migrating project definitions to new standards, cleaning up source code warnings, upgrading NuGet packages, and modernizing old services to use updated authentication and authorization methods.
• Additional work may involve build pipeline migrations and infrastructure-level improvements, with a strong emphasis on C# and cloud experience, covering both .NET Framework and .NET Core.
• Gather and analyze system requirements, document specifications, and develop software solutions to meet client needs.
• Analyze and review enhancement requests and specifications.
• Implement system software and customize to client requirements.
• Prepare detailed software specifications and test plans.
• Code new programs to client's specifications and create test data for testing.
• Modify existing programs to new standards and conduct unit testing of developed programs.
• Create migration packages for system testing, user testing, and implementation.
• Provide quality assurance reviews.
• Perform post-implementation validation of software and resolve any bugs found during testing.

Candidate Requirements

• Must have strong technical skills in C#, .NET, cloud services, and Infrastructure as Code.
• Excessive job hopping (e.g., changing jobs every month over the past two years) is considered a red flag.
• Prior experience with large-scale enterprise systems is preferred.

Best vs. Average Candidate

Experience splitting or migrating workloads to new reposit