In 1998, Porsanger began working as an associate professor at the Center for Sami Studies at the University of Tromsø. In 2000, she was promoted to researcher and lecturer, and in 2005, became a senior researcher. Her research on oral and written sources of the Eastern Sami indigenous religion from the 16th to the 20th centuries led to her doctoral dissertation, "Bassejoga čáhci": Gáldut nuortasámiid eamioskkoldaga birra álgoálbmotmetodologiijaid olis (Indigenous Methodology), which she defended at the University of Tromsø in January 2006. It was the first public defense to have taken place in a Sami language in Norway.[2] Porsanger has said that the inspiration for the assignment came from being frustrated at how little has been written about the Eastern Sami culture and religion, and that what was written was "unjustly generalized".[1]
Porsanger's research interests include the decolonization of research, the design of indigenous methodology, research ethics, Sami research history, and the history and spiritual culture of the Eastern Sami. She was subsequently employed at the Sámi University of Applied Sciences in Kautokeino, where, since 2010, she has led a research project for the development of methodology, documentation, preservation, protection and storage of Årbediehtu (traditional Sami knowledge). On August 1, 2011, she became rector at the college, a position she held until 2015. Porsanger has also been a member of the panel of experts for the United Nations Permanent Forum on Indigenous Issues.