Case Study: OneMain Financial achieves API-led integration and 200+ production APIs with MuleSoft

Why a C4E is critical to an integration strategy’s success

OneMain Financial, the largest lending‑exclusive financial company in the U.S. with 1,500+ branches, needed to modernize its integration landscape to support omnichannel customer experiences. Their environment had grown into 37 Java applications with roughly 1,000 point‑to‑point integrations and only two full‑time developers, creating brittle, hard‑to‑manage systems and a need for an API‑led approach and organizational buy‑in.

They adopted MuleSoft beginning in 2018, created a Center for Enablement (C4E) to drive training and standards, built CI/CD, and re‑architected around an API‑led experience→process→system model. As a result they expanded their integration team, converted legacy endpoints into reusable APIs, improved monitoring and reporting, and by 2020 had 200+ APIs in production—surpassing the value of legacy Java services and setting a course to retire them.

OneMain Financial

Erin Kieffner

Director of Service Enablement