Three years ago, Winston Weinberg was a junior lawyer at O’Melveny & Myers in Los Angeles. Now, he’s running a $US5 billion ($7.55 billion) company with about 400 staff – and hanging on for dear life.

“Every six months, you have to change how you’re running the company. That’s what I’ve found,” he says. “I go through a massive wake-up period every six months where I’m, like, these things that I’m doing aren’t going to scale any more.”