Senior Software Engineer – (C#, .NET)

OneMain Financial; Salt Lake City (UT); On-site; USD 90,000 - 130,000; Full time

Job summary

OneMain Financial in the United States seeks an experienced .NET software engineer to contribute to enterprise systems including Loan Origination and Servicing, and customer-facing apps such as omfauto.com and rateworks.com.

You will design scalable, secure backend services, implement RESTful APIs, collaborate via code reviews, and help modernize legacy systems while mentoring teammates in DevOps practices.

Qualifications

• 3–5+ years of enterprise-grade .NET development experience.
• Strong skills in T-SQL, C#, and .NET Framework backend design.
• Understanding of distributed multi-tier architectures.
• Hands-on with WPF/XAML, LINQ, MVVM, WebAPI; exposure to React or Angular beneficial.
• Proficient in RESTful API design, JSON and XML integrations.

Responsibilities

• Contribute to architecture and development of Loan Origination and Servicing systems and customer apps.
• Ensure scalable, maintainable, and secure software within projects.
• Implement APIs, middleware, and integrations with internal/external tools like Twilio Flex.
• Participate in code reviews, design discussions, and pairing sessions.
• Support automation, CI strategies, and DevOps practices to improve reliability.
• Assist in modernizing legacy systems and boosting scalability.
• Troubleshoot and tune performance to maintain system health.

Skills

.NET

T-SQL

C#

WebAPI

RESTful API design

JSON/XML integrations

MVVM

WPF/XAML

DevOps practices

Agile

Education

Bachelor’s degree in Computer Science, Engineering, or related field

Tools

React

Angular

Job description

Key Responsibilities

• Contribute to the architecture and development of key systems including Loan Origination Systems, Loan Servicing Systems, and customer-facing applications (e.g., omfauto.com, foursight.com, rateworks.com).
• Ensure scalable, maintainable, and secure software design within assigned projects.
• Implement APIs, middleware services, and integrations with internal and external tools such as Twilio Flex.
• Collaborate with peers through code reviews, design discussions, and pairing sessions.
• Support automation and continuous integration strategies to improve development efficiency and reliability.
• Assist in technical initiatives to modernize legacy systems and improve scalability.
• Participate in troubleshooting and performance tuning to maintain system health.

What Sets You Apart

• 3-5+ years of experience developing enterprise-grade applications in .NET.
• Strong skills in T-SQL, C#, and the .NET Framework with experience in backend service design.
• Understanding of distributed systems and multi-tier application architectures.
• Hands-on experience with WPF/XAML, LINQ, MVVM, and WebAPI; exposure to React or Angular is a plus.
• Proficiency in RESTful API design, JSON, and XML integrations.
• Ability to explain technical concepts clearly across teams.
• Experience working in Agile environments with DevOps practices.
• Bachelor’s degree in Computer Science, Engineering, or related field.
• Interest in mentoring peers and promoting modern development practices.

OneMain Holdings, Inc. is an Equal Employment Opportunity (EEO) employer. Qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship status, color, creed, culture, disability, ethnicity, gender, gender identity or expression, genetic information or history, marital status, military status, national origin, nationality, pregnancy, race, religion, sex, sexual orientation, socioeconomic status, transgender or on any other basis protected by law.

OneMain Financial (NYSE: OMF) is the leader in offering nonprime customers responsible access to credit and is dedicated to improving the financial well-being of hardworking Americans. Since 1912, we've looked beyond credit scores to help people get the money they need today and reach their goals for tomorrow. Our growing suite of personal loans, credit cards and other products help people borrow better and work toward a brighter future. In our more than 1300 community branches and across the U.S., team members help millions of customers solve critical financial needs, including debt consolidation, home and auto repairs, medical procedures and extending household budgets. We meet customers where they want to be - in person, by phone and online. At every level, we're committed to an inclusive culture, career development and impacting the communities where we live and work. Getting people to a better place has made us a better company for over a century. There's never been a better time to shine with OneMain.