View from the Top: Meet 6 Tuck Alumni CEOs

Tuck alumni at the helm reflect on the skills, values, and experiences that define them as leaders.

Many Tuck alumni can trace their earliest lessons in leadership to first-year study groups where they learned firsthand the power of diverse teams working together toward a common goal.

Others hearken back to what they learned in the classroom from faculty titans like long-time management communications professor Mary Munter or accounting professor John Shank. Wherever the learning first began, most will agree that their hardest-won lessons in leadership were gained through practice, by speaking up and taking risks, sometimes failing, and having the humility to get up and try again. The two-year Tuck experience marks only the beginning of a lifelong journey in wise, decisive leadership.

To better understand what successful leadership requires in today’s rapidly changing world of business, we spoke with six alumni CEOs leading the way in food, retail, fitness, finance, and health care.

The Decisive Risk-Taker

Karen Colberg T’91

CEO, King Arthur Baking Co.

“Humility is so important. I don’t have all the answers, but I’m willing to ask a lot of questions and I’m willing to listen. I’m also willing to make mistakes and learn from them. As a leader, I want people to feel like they can take risks and make mistakes as well.”

As she reflects on her leadership journey, King Arthur Baking Company CEO Karen Colberg T’91 can identify several key inflection points.

One of them occurred early in her career at the American retailer GAP. After graduating from Tuck, Colberg networked tirelessly for a financial planning and analysis role at the company where she was the first MBA hired. The position entailed a lot of top-down planning and budgeting, which Colberg excelled at. But after a couple of years, she was craving a new challenge.

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The Resilient Founder

Sarah Ketterer T’87

CEO, Causeway Capital Management

“I left [Tuck] completely convinced that teamwork was the avenue to a far better outcome than anything I could hope to achieve individually.”

When she chose to attend Tuck, Sarah Ketterer T’87 was yearning for knowledge beyond the world of corporate finance.

In her two years in Hanover, she gained a more well-rounded understanding of business and a deeper “toolkit” as well, but looking back, Ketterer says the greatest benefit she received from Tuck was a dramatic shift in perspective.

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The Strategic Operator

Michael Aragon T’01

Senior Advisor to CEO, Lululemon; Former CEO, MIRROR

“Team building is what I focus on most. How do you find super high agency people? How do you set goals for them? How do you set a vision and disseminate it throughout an organization so everyone is marching in the same direction?”

During a business career spanning more than two decades, Michael Aragon T’01 has been at the forefront of technological innovations shaping the way we think about digital content and community.

In January 2022, he became CEO of MIRROR and lululemon digital fitness, responsible for building the product and platform serving the active fitness community on MIRROR, which streams live and on-demand interactive classes to users in their homes through a sleek responsive display. Aragon says the opportunity to leverage his deep experience in strategy and operations, digital marketing, and technology to lead a brand focused on helping people live better and healthier lives was an easy sell.

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The People-First Manager

Luis Felipe Castellanos T’98

CEO, Interbank

“Dream big. Never let an opportunity pass. If you have the skills, the training, and the hunger to do things that change the world, go after those things.”

Luis Felipe Castellanos T’98 was just 40 years old when he became CEO of Interbank, one of Perú’s leading financial institutions. Since assuming the role in 2011, he has led the firm through a successful IPO in the NYSE and earned Interbank consistent recognition as one of the nation’s best places to work.

Despite the undeniable success he has achieved, Castellanos admits he initially felt overwhelmed by the responsibility the role would entail.  

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The Globally-Inspired Leader

Nancy Pak TEE’11

former CEO, Walden Local Meat Co. and Tate’s Bake Shop; Board Member, Columbia College Women

“Staying steadfast is key, especially in moments of uncertainty. If you look and act panicked, you’re not doing what you should be doing to bring folks together and reassure them.”

Nancy Pak TEE’11 had spent several years in Bangkok, Thailand as a marketing director for the greater Asia division of Colgate-Palmolive when she was selected for Tuck Executive Education’s Global Leadership program.

Unfolding over the course of an academic year, Global Leadership invites a consortium of non-competing companies to convene on campus in Hanover—as well as on-location in foreign markets like India—where they engage in immersive learning experiences designed to prepare high-potential executives for global leadership roles.

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The Health Care Revolutionary

Ismael Ortega MHCDS’22


“[In health care] there are opportunities to innovate and improve and make a meaningful impact in someone’s day-to-day life.”

After he earned his MBA, Ismael Ortega, MHCDS’22, began his career working in hedge funds. But he couldn’t imagine spending his life sitting in front of six computer screens for 16 hours a day. So he began thinking about other career paths. Health care attracted him because of its complexity. “There are opportunities to innovate and improve,” he says, “and make a meaningful impact in someone’s day-to-day life.”

He got a job at CHRISTUS, an international network of hospitals and medical centers, in its main office in Dallas. The team there was a small one that worked across many fields, and he was able to work on a variety of projects, including performance improvement, nursing, and ambulatory surgery. He realized he was more interested in operations work than accounting and finance. In conversations with Jeff Puckett, the CHRISTUS COO, Jeff encouraged him to broaden his skill set, and in 2020, he began looking for a program that would help him do just that.

Dartmouth’s Master of Health Care Delivery Science, a joint degree program between Tuck and the Geisel School of Medicine, appealed to him because it was designed for people like him who had already started their careers. He was also attracted to the diversity of the cohort: he would have a chance to work not just with other administrators, but also entrepreneurs and physicians.

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This story appeared in print in the winter 2024 issue of Tuck Today magazine.