From the Calcalist interview:

“Silicon is unforgiving,” Mr. Srouji said. “My team is already working on the chips you’re going to see in 2020. You make bets. We have the system and the software. We have better knowledge versus external chipmakers about where things are going to end up. Since we own the silicon, we own the software, the operating system and everything else, we deliver, always. We deliver for the exact specification of iOS and nothing else. We don’t have to worry about other operating systems.”

And:

In 2013, Apple acquired PrimeSense, an Israeli company developing hardware for 3D sensing, and many industry observers speculated about the Apple reasoning for the investment. Mr. Srouji said the team from PrimeSense was involved in the development of Face ID as well as other new features for Apple devices.

“The team in Israel is a key part of the overall engineering team in the U.S. and other areas of the world – wherever we have our R&D,” he said. “The things they do are key to any device we ship, to all devices.”

I found every bit of this interview fascinating, especially the insight into incorporating the work being done in Israel with the main body of R&D being done in Cupertino.