Ostling is a former partner and senior leader at Ernst & Young LLP (EY), serving in leadership roles from 1999 until her retirement in 2021. She most recently served as the professional practice director for EY's U.S. East Region, and before that as deputy director of global assurance professional practice - accounting. She also held leadership positions for Citigroup Inc. and the Financial Accounting Standards Board. She currently serves on the boards of Circle Internet Financial LLC and Varsity Brands Inc.