Senior Software Engineer - Enterprise .NET & API Architect

OneMain Financial; West Valley City (UT); On-site; USD 90,000 - 120,000; Full time

Job summary

OneMain Financial is seeking a software engineer to advance enterprise-grade applications in .NET. You will contribute to architecture and backend service design, building scalable loan origination and servicing systems, and customer-facing platforms.

Emphasis on RESTful APIs, React/Angular exposure, and DevOps practices to improve reliability. You will work in an Agile team, participate in code reviews, mentoring, and pair programming, and help modernize legacy systems while maintaining high

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.

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

C#

.NET

Distributed systems

Multi-tier architecture

Agile

DevOps

Code reviews

Mentoring

Education

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

Tools

T-SQL

WPF/XAML

LINQ

MVVM

WebAPI

RESTful API design

Job description

OneMain Financial is seeking a software engineer to advance enterprise-grade applications in .NET. You will contribute to architecture and backend service design, building scalable loan origination and servicing systems, and customer-facing platforms.

Emphasis on RESTful APIs, React/Angular exposure, and DevOps practices to improve reliability. You will work in an Agile team, participate in code reviews, mentoring, and pair programming, and help modernize legacy systems while maintaining high