The speculation intensified after Apple’s chief operating officer Jeff Williams, once considered Cook’s natural successor, stepped down from operational responsibilities in July and will leave the company by year’s end. With Williams out of contention, Gurman says Ternus has emerged as “the most likely heir apparent.”

Ternus brings a combination of technical expertise and institutional knowledge to the succession conversation. According to his LinkedIn profile, the mechanical engineer joined Apple’s product design team in 2001 and has overseen hardware engineering for virtually every major product in the company’s current portfolio. His fingerprints are on every generation of iPad, the latest iPhone lineup, and AirPods. He also played a crucial role in the Mac’s transition to Apple silicon. He’s also played a prominent role during Apple’s most recent keynotes, introducing products like the new iPhone Air.

The timing of Ternus’s increased visibility isn’t coincidental. Apple’s public relations teams have begun “putting the spotlight on Ternus,” according to Gurman, signaling the company may be preparing for a gradual transition of power. Beyond product launches, Ternus has taken on responsibilities that extend well beyond traditional hardware engineering, influencing product roadmaps, features, and strategic decisions typically reserved for more senior executives.

At 50 years old, Ternus mirrors Cook’s age when he became CEO in 2011, positioning him for potentially a decade or more of leadership. This longevity factor appeals to Apple’s board of directors, who prefer stability in leadership transitions. His engineering background also matches where Apple is going as a company, exploring emerging technologies like artificial intelligence and mixed reality.

Ternus’ path to Cupertino

Born in 1975, Ternus’s journey to the top of Apple began at the University of Pennsylvania, where he distinguished himself both academically and athletically. He graduated in 1997 with a Bachelor of Science in Engineering, majoring in mechanical engineering. But Ternus wasn’t just focused on his studies—he was a competitive swimmer who made his mark in the pool.

A 1994 report in The Daily Pennsylvanian revealed Ternus’s athletic prowess when he won both the 50-meter freestyle and 200-meter individual medley at a university swimming competition. More remarkably, Ternus is an “all-time letter winner” for the UPenn men’s swimming team, representing the varsity swim team a record number of times.

The early years: From VR to Apple

After graduation, Ternus joined Virtual Research Systems as a mechanical engineer. Virtual Research Systems, while not widely known today, was part of the early virtual-reality wave of the 1980s and 1990s, working on VR headsets and immersive technologies. This four-year stint exposed Ternus to cutting-edge display technology and human-computer interfaces—experience that would prove invaluable during his later work on products like the Apple Vision Pro.

Ternus joined Apple’s product design team in 2001, at a pivotal moment in the company’s history. Steve Jobs had returned, the iMac had revitalized the company, and Apple was preparing to launch products that would redefine entire industries. Starting as a relatively junior member of the product design team, Ternus initially worked on external Mac monitors.

By 2013, Ternus had been promoted to vice president of hardware engineering, initially overseeing AirPods, Mac, and iPad development. His portfolio expanded in 2020 when he took charge of iPhone hardware engineering, previously overseen directly by Dan Riccio. When Riccio stepped down in January 2021 to focus on the Apple Vision Pro project, Ternus was promoted to senior vice president of hardware engineering, making him a member of Apple’s executive team.

Apple’s public relations teams have begun “putting the spotlight on Ternus,” according to Gurman, signaling the company may be preparing for a gradual transition of power. This shift is evident in Ternus’s increased visibility at product launches and industry events. He has become a regular presenter at Apple’s keynote events, revealing refreshes of the iMac and MacBook Pro, introducing the 2018 iPad Pros, unveiling the iMac Pro, and presenting the completely redesigned 2019 Mac Pro. Crucially, Ternus was also responsible for unveiling Apple Silicon to the world, as well as the new iPhone Air.

“Ternus stands out,” Gurman wrote in his latest report. “He’s charismatic and well-regarded by Apple loyalists and trusted by Cook, who has granted Ternus more responsibilities. The executive has emerged as a key decision-maker on product road maps, features and strategies, extending his influence beyond the traditional scope of a hardware engineering chief.”

“When Apple began selling the iPhone 17 lineup last month, it was Ternus who ushered in customers to the company’s Regent Street store in London (a role Cook served at Apple’s Fifth Avenue location),” Gurman continued.

Apple’s leadership in transition

The succession question has gained urgency as Apple faces broader executive turnover. John Giannandrea, the senior vice president overseeing Apple’s AI strategy, reportedly has an uncertain future following setbacks with Siri development, according to Gurman, who added that hardware technologies chief Johny Srouji is “evaluating his future,” and environmental policy leader Lisa Jackson is also considering retirement.

For a company that has prided itself on organizational stability throughout Cook’s tenure, the simultaneous departure of multiple senior executives marks a significant shift. Cook himself has given mixed signals about retirement plans, telling CNBC in January that he can’t envision “doing nothing” and will “always want to work.” However, Bloomberg reports Cook may eventually transition to a chairman role, similar to moves by Jeff Bezos at Amazon and Bill Gates at Microsoft.

The choice of Ternus would represent Apple’s preference for promoting from within rather than seeking external leadership. It would also signal a shift toward prioritizing technical innovation over purely operational excellence, as the company seeks to reinvigorate product categories beyond the iPhone that generates the majority of its revenue. The company’s struggles with the Apple Vision Pro and its efforts to compete in artificial intelligence suggest technical leadership may be exactly what Apple needs for its next chapter.

For this story, Fortune used generative AI to help with an initial draft. An editor verified the accuracy of the information before publishing.