Tim Cook's 15-year tenure at the helm of Apple officially concluded on Monday. In his final act as CEO, he dispatched an emotional yet composed farewell letter to all employees, marking the transition of leadership at the world's most valuable tech company.

According to renowned Apple insider Mark Gurman, Cook sent the internal memo on his last day in the role. In the message, he affirmed he is "not leaving Apple," merely stepping aside from a position he "loved deeply," while confessing he will "miss this job immensely." He also expressed unwavering confidence in his successor, John Ternus, noting that few people understand what it takes to build world-changing products as well as John does, and that he looks forward to his leadership with great anticipation.

Cook will now continue his work at Apple in the capacity of Executive Chairman, with responsibilities spanning government relations and global communications. This arrangement ensures he retains significant influence over corporate strategy and external affairs.

15 Years at the Helm: From Successor to Record-Setter

In August 2011, Cook took over as CEO of Apple shortly before the passing of Steve Jobs, stepping into the role of leading the world's most valuable technology enterprise. His tenure, spanning an unprecedented 15 years, now stands as the longest in Apple's history.

Under his stewardship, Apple launched two entirely new product categories with Apple Watch and AirPods, while dramatically expanding the iPhone, iPad, and Mac lines. He guided the company from a hardware-focused computer and smartphone maker into a sprawling ecosystem encompassing hardware, software, and services.

In his farewell letter, Cook attributed Apple's success to the power of its corporate culture rather than individual achievement. "This company has proven that corporate culture can overcome anything," he wrote, crediting employees' belief in their mission as the root of Apple's extraordinary character. He invoked Jobs' famous mantra about "making a dent in the universe," emphasizing that Apple's strength stems from the shared values and worldview of its team members.

On the passing of the baton, Cook was explicit. He described Ternus as "smart, exceptional, and highly capable," stating that handing over the reins brings him a deep sense of reassurance.

New Role: Not Leaving, Just Moving Over

Cook was emphatic in his letter that "I am not leaving Apple," directly countering speculation of a complete exit. In his new position as Executive Chairman, he is expected to remain actively involved in select core matters, particularly in global policy communications and government relations—an area he has personally managed throughout his tenure.

For Apple, this leadership transition carries significance beyond personnel changes. Ternus inherits the challenge of sustaining product innovation momentum and charting a new course for Apple amidst the surge of artificial intelligence. Cook's continued presence as Executive Chairman provides a stabilizing buffer during this transition period.

Appendix: Cook's Full Farewell Letter to All Apple Employees

Team,

Today is my last day as Chief Executive Officer of Apple.

I always knew this day would come, but now that it's here, writing these words still feels surreal.

I love this company, and I love every single member of this team. I couldn't let this day pass without writing to all of you—to thank you for the overwhelming kindness you've shown me, for your steadfast dedication day in and day out, and for the privilege of being your leader throughout this extraordinary journey.

Frankly, whatever the outside world credits me with, it all belongs to you. You bring out the best in me. In my entire life, I have never worked with a team this remarkable, and I witness your excellence every single day.

Apple possesses a truly unique quality. What I'm most proud of can never be captured in an annual report. This company has proven that corporate culture can overcome anything. We share a common belief: that what we create matters; that we have both the opportunity and the responsibility to make the world a better place.

This mission is part of Apple's extraordinary essence. Apple nurtures this belief, but I believe it was rooted in each of you long before you joined. It's what brought you here, and it's what drives you every day.

Together, we've created things that none of us could have imagined or achieved alone. That's the secret to our success: we lift each other up.

As Steve once said, we get to make our mark on the universe because of our character, our beliefs, our values, and our view of the world. How fortunate we are—how fortunate I am.

As you know, I'm not leaving Apple. I'm simply stepping down from a role I have loved beyond measure. Although I feel complete peace with my decision, I will miss this job immensely. I will miss leading you and walking alongside you through every chapter. At the same time, handing the reins to someone as smart, exceptional, and capable as John (Ternus) brings me great confidence. Few people understand what it takes to build products that change the world as well as John does, and I am filled with anticipation for his leadership.

Please know that I am deeply grateful to all of you. Serving as your CEO has been the greatest honor of my life. Above all, I hope you continue to take pride in being part of this extraordinary Apple family and always give your all. When we pour ourselves into our work, care for one another, and stay focused on the people we serve, the impact we can create is limitless.

I look forward to seeing you in my new role—on the Apple campus, and around the world.

With everything I have,

Tim