Since its founding in 2011, Depop, the London-based fashion resale app, has been making circular fashion “accessible and aspirational” to the mainstream consumer, says CEO Peter Semple. The community-driven online marketplace now has more than 7 million active buyers—nearly 90% of whom are younger than 34. “It is ideally a net good for the world if we're all collectively teaching people to think about secondhand first,” Semple says. After 15 years, Depop has become one of the fastest-growing resale platforms in the U.S. and has put what Semple calls its “money, intention, and creativity” behind finding ways to make sustainable shopping as exciting as buying new—including investing in AI-powered tools that make transactions easier for both buyers and sellers, as well as building “a place for self-expression, connectivity, and the engaging aspects of social media—ideally without the detrimental effect that [it] can have,” says Semple.…