Head of Upper School Audrius Barzdukas will leave Harvard-Westlake to accept the position of Head of School at Poly Prep Country Day School in Brooklyn, New York, President Rick Commons said in an email sent to all faculty, students and parents Wednesday.

Director of Studies Elizabeth Resnick will serve as Interim Head of Upper School for the 2016-17 school year while the administration conducts a nationwide search to fill the position.

Barzdukas has been at Harvard-Westlake for 12 years, starting as the Head of Athletics, and has served his current position for four years.

“In this role, he has built trust and teamwork among the upper school faculty and staff, while empowering his colleagues to try new ideas and approaches,” Commons wrote.

Before her time at Harvard-Westlake, Resnick served as Director of Upper School at Crossroads School and as Academic Dean at Sage Hill School before that. She earned her undergraduate degree in comparative government at Harvard University, her master’s degree at Dartmouth University, and an M.B.A. at UCLA Anderson School, the email said.

“We are grateful to [Resnick] for her readiness to step into this important role next year, and we are grateful to [Barzdukas] for his visionary leadership,” Commons wrote.