A new era is beginning at Apple.

John Ternus is set to take over as chief executive officer on 1 September, succeeding Tim Cook after 15 years at the helm of the iPhone maker and putting a longtime hardware engineer in charge of one of the world’s most valuable technology companies.

Apple announced the succession in April following what it described as a long-term planning process unanimously approved by its board.

Cook, who has served as CEO since succeeding Apple co-founder Steve Jobs in 2011, is not leaving the company. He will become executive chairman of Apple’s board and continue assisting the company in certain areas, including engagement with policymakers around the world.

Ternus will also join Apple’s board on 1 September.

The transition puts an engineer with 25 years of experience inside Apple at the top of the company at a critical point in its history.

Ternus joined Apple’s product design team in 2001 before becoming vice president of Hardware Engineering in 2013. He was promoted to senior vice president of Hardware Engineering and joined Apple’s executive team in 2021.

He currently oversees hardware engineering across virtually Apple’s entire product portfolio, including the iPhone, iPad, Mac, Apple Watch, AirPods and Apple Vision Pro.

Before joining Apple, Ternus worked as a mechanical engineer at Virtual Research Systems. He earned a bachelor’s degree in mechanical engineering from the University of Pennsylvania.

His appointment also returns Apple to an engineer-led chief executive at a time when the company is navigating rapid changes brought by artificial intelligence.

Ternus inherits an Apple dramatically larger than the company Cook took over in 2011.

According to Apple, its market capitalization grew from about $350 billion when Cook became CEO to around $4-trillion, while annual revenue increased from $108-billion in fiscal 2011 to more than $416-billion in fiscal 2025.

Cook’s tenure also saw Apple expand beyond the iPhone, iPad and Mac with products including the Apple Watch, AirPods and Vision Pro, while building services such as Apple Music, Apple Pay and Apple TV.

One of the most consequential changes under Cook was Apple’s move away from Intel processors in the Mac toward its own Apple silicon, giving the company greater control over the hardware and software powering its devices.

That hardware-focused transformation is familiar territory for Ternus.

As Apple’s hardware engineering chief, he has overseen engineering work across the company’s major product categories and played a prominent role in product launches in recent years.

But the incoming CEO will also inherit challenges that extend far beyond hardware.

Artificial intelligence is reshaping the technology industry, putting pressure on Apple to demonstrate how AI will transform the iPhone and its broader ecosystem as rivals race to build increasingly capable AI products.

Ternus will also have to navigate regulatory pressure, geopolitical tensions, Apple’s vast global supply chain and the challenge of finding new products capable of complementing a business still heavily dependent on the iPhone.

Cook has publicly thrown his support behind his successor.

“John Ternus has the mind of an engineer, the soul of an innovator, and the heart to lead with integrity and with honor,” Cook said when Apple announced the transition.

Ternus, meanwhile, said he was “profoundly grateful” for the opportunity to lead the company where he has spent nearly his entire career.

“Having spent almost my entire career at Apple, I have been lucky to have worked under Steve Jobs and to have had Tim Cook as my mentor,” he said.

Ternus will become CEO at roughly the same age Cook was when Jobs handed him control of Apple in 2011.