Pathirana began his career at Uruwala Tea Factory as an Office Trainee and later as a Factory Trainee from 1999 to 2000. From 2001 to 2002, he served as an Assistant Tea Factory Officer at Kodagoda Tea Factory, followed by a tenure as Factory Officer at Gangani Tea Factory from 2002 to 2004.

Between 2004 and 2006, he worked as a Factory Officer at Green House Tea Factory, and subsequently held the same position at Dishan Valley Tea Factory for six months in 2006. He then joined Yalta Tea Factory as a Factory Officer, serving there from 2006 to 2010, before being appointed Factory Manager at Kandagastalawa in 2010.

From 2010 to 2016, he was employed at Katanwila Tea Factory as a Factory Officer, after which he joined LCBL in 2017 as a Manufacturing Advisor.

In January 2023, Pathirana successfully completed the Tea Manufacture Course at the University of Ruhuna, earning a Certificate in Scientific Tea Manufacturing and Quality Management.