GGV Capital’s Hans Tung and Zara Zhang interview Yinglian Xie and Fang Yu, the co-founders of DataVisor, a fast-growing startup in Silicon Valley that provides big data security analytics for consumer-facing websites and apps. Its customers include some of the largest companies in the world, such as Alibaba, Dianping, Pinterest, Yelp, and Bytedance (a.k.a. Toutiao), among others. Both Yinglian and Fang have decades of experience in internet security, specifically on fighting large-scale attacks to online services, such as fraudulent online payments, spamming, user hijacking, search-result poisoning, etc. They were both senior researchers at Microsoft for many years before starting DataVisor in 2013, and have filed over 20 patents. Yinglian received her Ph.D. in computer science from CMU and a Bachelor’s degree from Peking University. Fang holds a Ph.D. in computer science from Berkeley and a Bachelor’s degree from Fudan University.