Brian Chesky didn't know much about tech before starting Airbnb.

The now-38-year-old CEO majored in industrial design in college, and dabbled in hockey and bodybuilding in his 20s. But now, he's grown an idea that stemmed from overbooked hotels into a multi-billion-dollar startup, and has become one of Silicon Valley's key players.

On Thursday, Airbnb announced it was planning to go public in 2020, the latest step for a company last valued at $31 billion.

Here's how the Brian Chesky, an upstate New York native, became one of the richest young tech founders in America: