In 1997, Ostrander became an assistant professor of history at John Brown University in Siloam Springs, Arkansas.
[2] In September 2002, he became the dean of undergraduate studies at John Brown University.
[4] Ostrander became Vice President for Academic Affairs & Professional Programs at the Council for Christian Colleges and Universities (CCCU), Washington, DC in 2015.
In 2021 he served as Assistant to the President for Academic Innovation at Westmont College in Santa Barbara, California.
Ostrander began his role as Executive Director for the Michigan Christian Study Center in 2023.