David Sacks joins Zenefits as COO

David Sacks, the founder and former CEO of Yammer, has joined fast-growing HR platform Zenefits, as well as investing an undisclosed amount and joining the company’s board.

In discussing the move from a possible full-time venture capitalist role at Andreessen Horowitz, Sacks said to Michael Carney, “For me, investing is a sign of my commitment to the company. If I’m going to invest all of my time, I wanted to make a financial investment as well.”

David Sacks is one of the smartest people I’ve met in the enterprise software space. And let’s not forget the $1.2 billion sale of Yammer to Microsoft along with his work as Paypal COO and selling his startup Geni.com to MyHeritage in 2012.

The hypergrowth at Zenefits is one reason that CEO Parker Conrad was happy to bring David aboard, once the idea was suggested by Andreessen Horowitz general partner and Zenefits board member Lars Dalgaard, who understands hypergrowth from his time at SuccessFactors.

Zenefits has been growing at an unimaginable rate. The user base has grown 1,600 percent this year — a 30 percent per month revenue growth — and now serves over 2,000 businesses in 47 states. At the beginning of the year the company had 15 employees. It now boasts 470. This is the scaling challenge that justifies bringing aboard a master, and Sack is that guy. Zenefits is now up there with Slack in growth rate.

And Sacks’ buying a chunk of the firm shows that he’s deeply committed to making Zenefits a world-beating multibillion dollar company.