In a bold move to reshape the way young people engage with fashion, Phoebe Gates and Sophia Kianni have unveiled their new venture: Phia, a digital fashion platform that focuses on secondhand shopping, resale, and sustainability. The startup blends high-tech functionality with Gen Z style sensibilities to make thrifting not just cool but incredibly convenient.
Gates and Kianni, both in their early twenties, co-founded Phia to tackle one of fashion’s biggest problems: waste and overconsumption. The fast fashion industry continues to accelerate, pushing out billions of garments each year. Consumers wear many of these pieces only a few times before they toss them. This cycle creates mountains of textile waste. Phia aims to disrupt this by creating a streamlined, digital-first platform that simplifies the resale of fashion items, especially among younger consumers.
Meet the Founders: Phoebe Gates and Sophia Kianni
Phoebe Gates, daughter of philanthropists Bill and Melinda Gates, has carved out her own voice in the worlds of fashion and social advocacy. She’s not simply riding on her family’s legacy—she’s forging her own path with education from Stanford and internships at major fashion houses. She loves experimenting with fashion, but she also stays vocal about climate change, sustainability, and gender equity.
Sophia Kianni, an Iranian-American climate activist, founded Climate Cardinals, a nonprofit that translates climate change content into over 100 languages. She also served as a U.N. Youth Advisor. Kianni uses fashion as a medium of expression and activism, often donning pieces that spark conversations.
Together, these two young women represent the intersection of fashion, sustainability, and technology. Their combined experience in social impact and public advocacy fuels Phia’s mission.
What Is Phia? A Rethink of the Resale Experience
Phia exists to make secondhand shopping as easy, fun, and aesthetically appealing as buying new clothes online.
Gates and Kianni didn’t just want to create another resale app. Instead, they focused on the user experience. Most resale platforms today—like Poshmark, Depop, or ThredUp—feel like marketplaces. Sellers list items manually, write detailed descriptions, and handle shipping. Buyers browse cluttered grids or scroll endlessly through mismatched listings.
Phia changes that with AI-powered curation, a clean and modern interface, and a “resale ready” feature. The app allows users to resell clothes almost instantly, straight from their purchase history or digital wardrobe.
Phia’s beta users can upload their items with one click, generate descriptions using AI, and even set recommended pricing through real-time trend data. The system tracks previous purchases from partner stores and suggests resale listings when the user no longer wears an item. It’s a digital wardrobe that manages itself.
The result? More people participate in the resale economy, fewer clothes end up in landfills, and sustainable shopping becomes part of everyday life.
Phia’s Sustainability Vision: Changing How Gen Z Shops
Phia goes beyond building a tech platform—it builds a movement. The startup aims to shift how Gen Z sees ownership and value in fashion.
Gates and Kianni built Phia on the principle that style shouldn’t come at the cost of the planet. They want their users to feel empowered, not guilty, when they shop. So instead of preaching about sustainability, Phia makes sustainable behavior easier than the unsustainable alternative.
They encourage circular fashion through:
- Integrated resale timelines that remind users when it’s time to rotate a garment.
- Community styling sessions that show how to style old clothes in new ways.
- Carbon footprint tracking on every listed item, showing how resale lowers environmental impact.
- Digital lookbooks that feature items from user wardrobes, not just professional models.
This approach makes sustainability accessible, stylish, and seamless—exactly how Gen Z wants it.
Beta Testing and Community Feedback
Phia launched its closed beta in March 2025 with a handpicked group of 2,000 early users. Most of them fall between the ages of 16 and 28—students, creators, fashion influencers, and digital natives.
Gates and Kianni designed Phia’s early features around this community’s needs. They conducted surveys, hosted roundtables, and monitored user behavior. From that research, they found three core demands:
- Speed – Young shoppers don’t want to spend 20 minutes listing an item.
- Aesthetics – The platform must look clean, modern, and Insta-worthy.
- Social Layering – Fashion is social, so resale should feel like a community, not a transaction.
Phia already integrates short-form video, styling challenges, and interactive profiles. It feels more like TikTok meets Vinted than a standard shopping app.
User response has been overwhelmingly positive. Many beta testers say Phia feels like a natural extension of their digital lives. “It’s the first time I’ve felt excited to resell my clothes,” said one college student during a community feedback session.
Funding, Growth Plans, and Future Roadmap
Phia currently operates as a bootstrapped venture, but Gates and Kianni confirmed they’ve begun conversations with impact-focused VCs and fashion accelerators. Their early traction and high-profile founding team have attracted interest from Silicon Valley and major fashion conglomerates.
They plan to open their Series A round by Q3 2025, aiming to raise around $10–15 million to scale engineering, hire content creators, and expand into new markets like the UK and Canada.
In terms of feature growth, Phia will launch:
- In-app resale analytics to show users how much they’ve earned and saved.
- Wardrobe sharing so friends can borrow or trade pieces digitally.
- Collaborations with upcycling designers who rework listed items into new collections.
The startup also plans to partner with sustainable brands and eco-conscious influencers to build a creator economy around slow fashion.
Why Phia Matters Now
In 2025, fashion sits at a crossroads. Fast fashion continues to dominate, but consumer awareness around environmental damage has never been higher. Brands can no longer greenwash their practices without backlash. Resale platforms like ThredUp and Depop laid the groundwork, but the next generation wants a smarter, slicker experience.
Phia offers just that. It taps into the circular economy, pairs it with creator culture, and packages it with highly functional tech. Gates and Kianni have not just identified a gap—they’ve designed a lifestyle around it.
By 2030, resale could make up more than 20% of the fashion market, according to several industry forecasts. With Phia, these two changemakers plan to own a big slice of that future.
Final Thoughts
Phoebe Gates and Sophia Kianni didn’t launch Phia as a side hustle or social experiment. They launched it to redefine how young people buy, wear, and resell fashion. Their approach feels modern, inclusive, and deeply aligned with the values of today’s youth.
As they gear up for the full public launch, Phia looks well-positioned to disrupt the resale game—and maybe even change fashion’s relationship with waste forever.