Sima Sistani has more than 20 years of experience innovating human-centric platforms for connection. Sima has started, operated, and scaled companies from startups to multinational corporations. She most recently served as the CEO of WeightWatchers where she architected and led its successful transformation from waning consumer retail company to leading digital health platform. In 2023, CNN Business honored Sima in their annual list of 11 leaders making big bets to move global business forward. In 2024 she was recognized by CNBC as a “Changemaker” for her leadership in transforming diet culture. Sima serves on the board of Best Buy and is a Professor at Duke University teaching Women's Leadership Lab.
Prior to her joining WW in March 2022, Sima was the Co-Founder and CEO of Houseparty, a communication app. Houseparty, which grew to over 100M users under her leadership, challenged the incumbent social media giants with its innovative approach to synchronous chat. Epic Games acquired the company in 2019. At Epic, Sima joined the senior leadership team where she was responsible for social products across Epic Games: including Fortnite, the world’s most popular game with over 650 million players.
Prior to founding Houseparty, Sima led Mobile Growth at Yahoo at a time when the company’s stock doubled in value. After Yahoo acquired Tumblr, Sima played a key role in bridging the two entities, as Head of Media for the microblogging and social media giant. During her tenure, Tumblr became the fastest-growing social network in active users in just 6 months. Sima is an Aspen Institute Henry Crown Fellow. She holds a BA from Duke University and an MBA from Northwestern University, Kellogg School of Management. Sima is a first generation American and lives in North Carolina with her husband and two children.
People often think being a CEO is about control, but it’s actually about clarity: clarity of vision, clarity of values, and clarity in communicating them. When we transformed a 60-year-old legacy consumer retail company into a leading-edge telehealth platform, it wasn’t about pushing a singular agenda. It was about bringing thousands of employees, a community of 4M+ members, and investors along for the journey. Change is never a solo act. It demands collective buy-in, and achieving that buy-in requires relentless clarity.
I listen to feedback actively and obsessively even when it’s uncomfortable. But it’s not just about listening; it's about staying endlessly curious! I would consider myself a culture vulture. I love scanning ahead to anticipate what's next, but that also means deeply understanding what's now. So that means I’m plugged in and consuming everything from niche podcasts and emerging TikTok trends to shamelessly keeping up with the zeitgeist (including late-night binges of Love Island and keeping tabs on the latest Lububu drop). I believe the best builders create from a place of authenticity and shared experience. If you’re not building with your customers, immersed in their worlds and able to anticipate their next moves, you’re probably not building for them.
I’m in what I call my “freedom era,” fully embracing a portfolio life. To me, that means intentionally designing a career and life that’s not defined by a single job title or path, but by a collection of meaningful projects, experiences, and contributions. I’m letting inspiration guide me, and it’s been incredibly energizing. Alongside my committed board work, I have gotten certified as a yoga teacher, developed and teaching a course at Duke called The Women’s Leadership Lab, and I’m deeply invested in exploring new ways to honor and support women, whether that’s through mentorship, investing, or building something entirely new. I am pursuing alignment vs outcomes.
It’s really a mix of three things that are interconnected: intuition, the courage to follow it fearlessly, and the resilience to bounce back if it doesn't work out. My intuition has been my best strategist. It's what led me to make bold, unconventional moves in my career. But intuition without action doesn’t get you anywhere, so I’ve learned to trust that gut pull even when it feels risky. And when those risks don’t pan out the way I envisioned, I redirect and move forward. The bounce-back muscle is what turns intuition into real progress.
I grew up watching Oprah on TV as a latchkey kid, unknowingly getting my first lessons in leadership and life from her. To now have the privilege of calling her a mentor is surreal. She’s built an empire by leading with curiosity, empathy, and an unwavering belief in her own voice. What I admire most is how she’s never been afraid to evolve in public, to shift and expand her purpose as she grows. She’s proof that success isn’t about fitting into someone else’s mold, but creating your own.
Aside from the obvious (friends, family, coffee), it’s my passport I can’t live without. It’s my reminder that the world is way bigger than my to-do list, and exploring new places is my favorite form of self-care. I love getting a little lost somewhere new.
I’m loving the female founder comeback stories. Women like Gregg Renfrew, Ty Haney, and Audrey Gelman are showing that you don’t have to be defined by one chapter. Female founders and CEOs are rarely given the same runway, patience, or benefit of the doubt that their male counterparts are. These women are rewriting what resilience and reinvention look like with a “second act” that is more powerful than the first. I want this to be more than a “trend.” I hope it becomes an inspiration for more women to reclaim their narrative, and a call for all female leaders to be given equitable space to build boldly without the fear of undue judgment or backlash.
I recently returned to “The Artist’s Way” by Julia Cameron. It has taught me creativity is not just a skill, but a discipline. And when you practice creativity it becomes a renewable resource that fuels everything else.
