Sion Jeon

Software Engineer at NMSI.INC

Los Angeles Metropolitan Area

About

Hello, I’m currently working as a Full Stack Developer at NMSI, a mortgage company based in LA/OC. I strive to develop with the user's perspective in mind, ensuring that our company and underwriters have a seamless experience.

Experience

  • Web Developer at NMSI INC.
    Jul 2024 - Present · 2 yrs 1 mo

    • Develop and maintain an enterprise Loan Origination System (LOS), ensuring high availability and performance for underwriting workflows. • Design and implement RESTful APIs in ASP.NET Core (.NET) to support loan processing (validation, workflow actions, and data exchange). • Integrate LOS with third-party financial agencies (e.g., Fannie Mae, Freddie Mac) to improve data exchange efficiency and support fraud-detection checks. • Implement an OCR-based AI validation system that reduced underwriters’ loan processing time by 30%+, minimizing manual document review. • Build an LLM integration for credit report retrieval, significantly reducing turnaround time for underwriting decisions. • Deliver scalable backend features on Azure, supporting document storage workflows on AWS S3.

  • Undergraduate Research Assistant at UbicompLAB (SCHU)
    Jun 2022 - Aug 2024 · 2 yrs 3 mos

    • Developed full-stack business websites using JavaScript and REST APIs, delivering features end-to-end from requirements to deployment. • Implemented CMS backend features for content management and client self-service. • Integrated third-party APIs (payments, analytics) to enhance site functionality and reporting. • Configured deployment environments (domains, DNS, hosting) and performed production maintenance.

  • Army sergeant at Republic of Korea Army
    Jan 2020 - Jul 2021 · 1 yr 7 mos

    • Developed and repaired night vision equipment, such as rifle-mounted night vision scopes and aiming devices