Born in South Korea to a family of esteemed doctors, Saeju Jeong's aspiration to help people and be an innovator was inherent from a young age. He began his entrepreneurial journey by founding South Korea’s first-ever heavy metal e-commerce business. However, it was the passing of his father, a renowned doctor, that redirected the course of his life and profoundly influenced Saeju's entrepreneurial and personal direction. It was his father’s experience in healthcare and reflection in his last moments that inspired Saeju to transform sick care into preventative care and give back the gift of time to people's lives.

In 2005, Saeju embarked on a pivotal journey to the United States. There, he met Artem Petakov, then working at Google, and together they shared a vision to promote healthier living, ultimately leading them to co-found Noom in 2008. Under Saeju's leadership as CEO for 17 years, Saeju secured $657MM in investment from prominent firms including Sequoia Capital and Silver Lake and spearheaded the development of the leading behavior change platform in the consumer healthcare market, leading thousands of employees and impacting millions of lives globally. Today, Noom is a central destination for holistic health, with four programs to effectively treat weight management, obesity care management, diabetes, and stress management. The company's success also extended to publishing, with "The Noom Mindset" becoming an overnight national bestseller, and "The Noom Kitchen" cookbook releasing on January 2, 2024.

Saeju’s leadership has been recognized through multiple prestigious accolades, including EY’s Entrepreneur of the Year in 2020, Harvard Business School’s Entrepreneurial Company of the Year in 2022, Goldman Sachs' Builders and Innovators Award in 2022, Inc.'s 500 Great Entrepreneurs in 2019, and is a regular attendee at the World Economic Forum’s annual meeting at Davos. Saeju has been featured in top-tier media including “How I Built This,” “Masters of Scale,” and an eight-page brand interview in Inc.

In July 2023, Saeju transitioned to his current role of Executive Chairman, continuing to shape Noom's vision and strategy​​.