Just four months after leading Twilio Inc. through the year's first tech IPO, Karyn Smith, the company's general counsel and corporate secretary, managed a unique secondary offering that benefited all employees and stockholders.

Who's the best leader you've seen in action and why?

The best leader I've personally worked with was Reggie Davis, who was my boss at Zynga. I learned so much from Reggie about how to build great teams and empower others to grow and scale in their own careers. He was not afraid to hire excellent people and to let them be excellent.