Segment

founders: calvin french-owen, peter reinhardt (ceo), ian storm taylor, ilya volodarsky $109 million Equity raised: Estimated 2017 revenue: more than $45 million

Lead investors: accel, e.ventures, gv, kleiner perkins caufield & byers, thrive capital, Y combinator continuity fund

What it does: makes systems that help companies collect and analyze customer data. when reinhardt and his cofounders posted their idea on Y combinator’s hacker news in December 2012, the community responded with a resounding yes. “i don’t think anyone had really built a product around this concept,” recalls reinhardt, 28, a forbes 30 under 30 alum. today segment has 175 employees, mostly in san francisco, and counts gap, crate & barrel, autodesk and instacart among its customers. it’s planning new products and an office in europe.