Senior Software Engineer - (C#, .NET)

Onemain; Salt Lake City (UT); On-site; USD 95,000 - 135,000; Full time

Job summary

OneMain Holdings, Inc. is seeking a seasoned .NET software engineer to contribute to the architecture and development of core systems such as loan origination and servicing platforms, and customer-facing applications.

You will work in a collaborative, Agile environment with DevOps practices, implement RESTful services, APIs, and integrations, and help modernize legacy systems while ensuring scalable, secure software across multi-tier architectures.

Qualifications

• 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.

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.

Skills

3-5+ years experience

T-SQL & C#

Distributed systems

WPF/XAML

LINQ

MVVM

WebAPI

React/Angular

RESTful APIs

JSON

XML

Communication

Agile

DevOps

Mentoring

Education

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

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.