One woman working to effect change from the investor side is Sonja Hoel Perkins, managing director of Menlo Ventures, and founder of Broadway Angels, an angel investment group whose 20 members "all happen to be women."
Perkins says she and her colleagues "invest in the best companies and the best people," but of the 30 companies they've invested in since 2010, 52 percent have a woman founder or CEO, a far higher percentage than any traditional VC firm. The members of Broadway Angels are senior women in venture capital with established track records and former c-level executives from companies including LinkedIn, Facebook, eBay and Salesforce. They vote with their own personal checkbooks—not everyone invests in all the same deals, but they share due diligence and deal flow. But the idea is, they'll find the absolute best companies to invest in, because they're more open to pitches by female founders.
Read MoreBet on women with Barclays' new index
"I just think there aren't enough role models," says Perkins of her decision to found Broadway Angels. "Instead of talking about how there aren't women in tech, just show women that there are women in tech." And Perkins says having a female-driven firm is proving to be a competitive advantage: "All the best women want to come to us because they want a women investor—we're definitely more approachable."
Read MorePutting good-old-boy network to the investor test
Meanwhile Hearsay CEO Clara Shih, named to CNBC's "The Next List" of leaders for the next 25 years is trying to impact change starting at her own company.
"We specifically try to recruit women and we are open-minded about women who may not have a programming background," she says.
One of Hearsay's top engineers started in customer support, and after noticing a problem she wanted to fix in the company's systems, she decided to teach herself how to program, Shih recalls.
Yet, the CEO also believes the solution to creating a more diverse tech workforce is starting early—that you have to "catch" young girls to instill confidence with these more male-dominated fields, early on.
Shih graduated No. 1 in computer science at Stanford University, so she—and many of the others here—is certainly a role model.