Ternus will take over as chief executive in September for Tim Cook, who turned Apple into a $4 trillion tech colossus during his 15-year run after the death of co-founder Steve Jobs.

Ternus faces challenges that will force him to step out of his comfort zone in hardware engineering. Beyond finding ways to keep Apple competitive in the artificial intelligence race, he will need to navigate supply chain questions and relationships with figures like President Donald Trump, who offered public praise for his predecessor on Tuesday.

Ternus, 50, has spent almost his entire career with Apple. He joined the company 25 years ago and has spent the past five years overseeing the engineering that underlies the iPhone, iPad and Mac.

It made him the prime contender to succeed Cook who on Monday, when Apple announced the change in leadership, hailed Ternus as “without question the right person to lead Apple into the future.”

Ternus worked on some of Apple’s signature products under Cook, including the Apple Watch, AirPods and Apple Vision Pro. He was also involved in the MacBook Neo, “arguably one of the most disruptive products” that Apple has released in a while, said Ben Wood, chief analyst at CCS Insight.

“This mentorship will undoubtedly ensure a smooth transition, and initially, I expect very few changes to the company’s strategy,” Wood said.

The appointment appeared to be carefully timed, following Apple’s 50th anniversary celebrations and ahead of its annual WWDC developers conference in June.

The change also arrives at a pivotal time for the Cupertino, California, company. While Cook led Apple through an iPhone-fueled era of prosperity, Apple has fallen behind in the AI race. Apple has stumbled in its efforts to deliver new features built on AI, as was promised nearly two years ago.

“The challenge for the new CEO is really to make sure Apple is able to crack AI as the new user interface and reinvent human machine interaction,” Forrester Research analyst Thomas Husson said.

Wood says attention at WWDC will be on the new CEO’s AI strategy, and what the company will do next after turning earlier this year to Google — an early leader in the AI race — to help make the iPhone’s virtual assistant Siri more conversational and versatile.

“A big strategic question is how far Apple will invest in building its own AI platform versus relying on other companies’ models and platforms,” Wood said.

Apple also faces a turbulent market amid geopolitical uncertainty, Wood said.

“The consumer electronics industry faces a perfect storm, with memory chip shortages and the war in the Middle East having widespread implications for consumer confidence. Apple will also need to decide how much it wants to continue its deep reliance on China for manufacturing,” he said.

Being Apple CEO will also require soft skills including developing relationships with important figures. Cook cultivated ties with Trump as he navigated the company through business challenges including Trump’s trade and tariff war targeting countries in Asia, where Apple has extensive manufacturing supply chains.

Trump noted his relationship with Cook in a social media post on Tuesday morning, writing that “it began with a phone call” at the beginning of his first term, when Cook asked for help with “a fairly large problem that only I, as President, could fix.”

“That was the beginning of a long and very nice relationship,” Trump said.

Ternus is not well known outside of the Apple universe. He joined the company in July 2001, according to his LinkedIn profile, which does not have any posts.

Before joining Apple, he spent four years as a mechanical engineer at Virtual Research Systems. He graduated in 1997 from the University of Pennsylvania, where he was a member of the swim team and for his senior project developed a mechanical feeding arm for quadriplegics controlled by head movements.

In a 2024 commencement speech to the university’s engineering school, Ternus said he was intimidated when he first started working at Apple and wasn’t sure he belonged. He learned to “always assume you’re as smart as anyone else in the room but never assume you know as much as they do.”

“There will always be new skills to master and new people to learn from,” he said.

Ternus said in Apple’s announcement that he was “humbled to step into this role, and I promise to lead with the values and vision that have come to define this special place for half a century.”