LONDON — Apple’s next CEO John Ternus is a company veteran who rose through the iPhone maker’s hardware engineering ranks but until now has maintained a low profile.

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 reign after the death of co-founder Steve Jobs.

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’s made him a 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 artificial intelligence 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.

Ternus will also be tested by host of other challenges that don’t involve his expertise in hardware.

“Apple faces a turbulent market amid geopolitical uncertainty and macroeconomic pressures,” 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.”

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.”