Apple today posted a touching open letter from Tim Cook on its website, in which he calls his time as CEO of Apple an “honor and a privilege”. He also describes incoming CEO, John Ternus, as a “brilliant engineer and thinker”. As announced today , Tim Cook will move to the executive chairman role in September. Ternus is being promoted from his prior role as SVP Hardware Engineering. Cook became Apple’s CEO in August 2011, after founder Steve Jobs had to retire from the position due to ill health. When Cook steps down in September, he will end a fifteen year run as leader of one of the biggest and most valuable companies in the world, with much of its meteoric rise happening under his watch. During his tenure, Cook oversaw the record growth of the iPhone business, a major expansion of Apple’s services division, the industry-leading era of Apple silicon, as well as launching new product categories like AirPods, Apple Watch, and Vision Pro.…