It’s 15 years since Sweden’s Spotify Technology SA, co-founded by Daniel Ek, launched its music streaming service as a legal all-you-can-eat middle ground between online piracy or paying $20 for an album. At the time, the music industry was slashing jobs and struggling with the MP3’s rise: In the digital domain, “copies are not just cheap, they are free,” technologist Kevin Kelly wrote in 2008.

Today, Ek is a billionaire, and streaming has helped the music biz get back to its pre-MP3 size. Yet Spotify is now cutting 1,500 jobs as the industry’s foundations get rocked again. Even with more than half a billion unique users, technology that seems to understand our listening tastes better than we do ourselves (the annual Spotify Wrapped is said to be cognitively “irresistible”), and more content than we could listen to in a lifetime, Ek faces an existential challenge: Is Spotify a financially sustainable business?