Maddy Yip
| Maddy Yip | |
| Occupation | Entrepreneur, machine learning engineer |
|---|---|
| Known for | Co-founding Retrofit |
Maddy Yip is an American entrepreneur and machine learning engineer who is the co-founder of Retrofit, a vintage fashion marketplace that uses artificial intelligence to curate and personalize secondhand and luxury resale inventory for online shoppers. Retrofit was part of the Y Combinator Winter 2025 (W25) batch.[1]
Career
Prior to co-founding Retrofit, Yip worked in machine learning at YouTube, a subsidiary of Google.[2]
Yip co-founded Retrofit in 2024 alongside Sandra Lifshits, who serves as CEO. The company operates as an AI-powered vintage marketplace that aggregates inventory from independent vintage stores and major resale platforms—including Depop, eBay, Poshmark, The RealReal, and Vestiaire Collective—into a single shopping experience. Retrofit's AI agents analyze social media trends, sales data, and individual user style preferences to surface relevant vintage items, aiming to eliminate the need for shoppers to manually search through thousands of listings across multiple platforms.[3]
The platform features a personal shopping assistant named Sophie, which interacts with users through a chat interface to help identify and recommend vintage pieces tailored to their tastes. Retrofit sources from both brick-and-mortar vintage shops and online resale marketplaces, positioning itself as a bridge between physical vintage retail and e-commerce.
Retrofit was one of 12 consumer startups selected for Y Combinator's W25 batch. The company launched publicly in February 2026. Lifshits prepared for the venture in part by volunteering at vintage stores in New York to better understand the operational challenges facing physical vintage retailers.
Yip has been recognized on lists including "The 50 Youngest Kid Entrepreneurs in the US" and a "40 Under 40" list, though the specific publications and years of these recognitions are not confirmed.
The company operates in the broader secondhand and resale fashion market, which has experienced significant growth in the United States and globally.
References
- ↑ "Retrofit Launches: A Vintage Marketplace Curated By AI". 'Huge Magazine}'. Retrieved 2026-03-19.
- ↑ "Retrofit (YC W25)". 'FounderTrace}'. Retrieved 2026-03-19.
- ↑ "Retrofit — Score vintage gems at the best prices, effortlessly". 'Retrofit}'. Retrieved 2026-03-19.