Between October 2002 and September 2006, she was a legal consultant for the private agricultural firm Kobzar in the Ivano-Frankivsk Oblast.

In 2004, she graduated from Vasyl Stefanyk Precarpathian National University with a degree in Economics and Entrepreneurship and is an accountant-economist.

Between January 2012 and September 2014, she was a part-time Associate Professor of Public Administration and Local Government of Ivano-Frankivsk National Technical University of Oil and Gas.

From February to April 2012, he was an adviser to the patronage service of the head of the Kolomyia District State Administration of the Ivano-Frankivsk Region.

From 17 September 2019 to 8 July 2021, Onyshchuk was the Deputy Head of the Ivano-Frankivsk Regional State Administration.