Founder and former Chief Technical Officer of PayPal who went on to help start up the review site Yelp.
He fled the Soviet Union with his family to avoid persecution.
He worked to prevent fraud at PayPal, creating one of the first CAPTCHA systems.
He married his girlfriend of eight years, Nellie Minkova, in 2008.
He was the co-executive producer of Thank You for Smoking starring Aaron Eckhart.