Not every first-time startup manages to nab early investors like Kris Jenner and Sara Blakely, but Phoebe Gates and Sophia Kianni, creators of Phia, aren’t just everyday app developers. Gates, daughter of Bill Gates, and Kianni, a 24-year-old environmental activist, have teamed up to create an A.I. shopping agent that takes a user’s search and steers them to secondhand and vintage options instead.
What do you think is your biggest contribution to culture?
Sophia Kianni: Empowering people to make better choices in their everyday lives and careers. That started with hundreds of youth fellows and thousands of volunteers at my nonprofit Climate Cardinals, and now extends to helping millions of shoppers through Phia and millions of viewers of [our podcast] The Burnouts build their dream careers.
Phoebe Gates: Being part of a generation of women who decided not to wait for permission. That shows up in how I build, who I hire, what I’m willing to say out loud. If there’s a younger woman watching and thinking, If she can, I can, that’s the contribution I care about most.
What do you want to see more of in your industry? Less of?
Kianni: I want to see more young disruptors using technology and new business models to rethink legacy industries. There’s so much untapped opportunity right now, and a new generation coming in with fresh perspectives and the willingness to build differently.
Gates: More women on both sides of the cap table. Today, less than 2 percent of venture funding goes to female founders. Women drive a huge share of consumer spending, and the industry should reflect and invest in that reality.
What are you looking forward to this year?
Kianni: Building the best team and the best product at Phia, getting a little better every day, and learning as much as I can along the way.
Gates: Watching resale go from niche to inevitable and building Phia into something much bigger than fashion. I’m especially excited to expand our brand partnerships, bring more luxury brands into the ecosystem, and build a larger, more connected community around them. We’ve only begun to scratch the surface.
What keeps you up at night?
Kianni: There’s so much opportunity right now, it almost feels infinite. I want to make sure I’m moving fast enough to actually meet it. Also, A.I. fascinates me.
Gates: Whether I’m becoming someone I’m proud of, not just in terms of what I’m building, but how I’m showing up for the people around me. The to-do list is easy to measure, but that personal growth piece is harder to track, and just as important.
What’s one book, work of art, or film that got you through an important moment in your life?
Kianni: I always go back to The Go-Giver. It reshaped how I see business early on, focusing less on outcomes and more on creating real value and helping people. That mindset has stayed with me and shows up in every partnership I build.
Gates: The Psychology of Money by Morgan Housel. As much as it’s about investing, it’s also about how people think, and how much of our decision-making is driven by things we’re not consciously aware of. I’m someone who looks at KPIs and systems and processes, and this book reminded me that behind every data point is a person with a whole set of experiences shaping their choices. It changed how I think about organizing work and life more broadly.
What question do you ask yourself most often while making your work?
Kianni: What is the fastest way that we can validate that this solves a problem?
Gates: What assumptions am I making that I haven’t tested yet?
When’s the last time you laughed hysterically?
Kianni: Watching our Burnouts Instagram reels and carousels. Our team is killing it. The guests have been so funny too. Rachel Zoe and Steve Madden’s clips had me LOLing.
Gates: My miniature dachshund Moose and my Ragdoll cats are in an ongoing cold war and the peace negotiations are not going well. There was a standoff last week. I couldn’t stop laughing.
What’s been the hardest part of your career so far?
Kianni: The responsibility. Building a team in my 20s and having people rely on us, I actually love it. I feel really grateful to be learning this much this early.
Gates: I don’t think you want the hardest parts of your career behind you. Those tough moments are what build you. So I’ll say this: launching Phia was the easy part. The hardest work is the part that doesn’t stop. And I mean that as a good thing.
To read more from the 2026 CULT100 honorees, see the full list here.
in your life?
