Hiemstra assumed his current position in 2022, having joined Uber in 2015. Since 2024, the company has had a particular focus on providing transport options to students and families, such as through Uber School in 2025, designed for school pick-up and drop-off in collaboration with Dubai’s Road and Transport Authority, and Uber Teens, which began operations in April 2024 across the U.A.E., Saudi Arabia, Qatar, and Jordan. In April 2025, Uber announced a partnership with Dubai’s Road and Transport Authority, alongside WeRide, to introduce autonomous vehicles to the emirate. Hiemstra was previously the general manager for Uber in sub-Saharan Africa.