Michael Safyan, Software Engineer at Google · Author has 9.5k answers and 5.7m answer views
Brin'sfather Michael brought the family to the USA from the Soviet Union because of open anti-Semitic discrimination there. Moment magazine says:
"The Brins were no different from their fellow immigrants in that being Jewish was an ethnic, not a religious experience. 'We felt our Jewishness in different ways, not by keeping kosher or going to synagogue. It is genetic,' explains Michael. 'We were not very religious. My wife doesn’t eat on Yom Kippur; I do.' Genia interjects: 'We always have a Passover dinner. We have a seder. I have the recipe for gefilte fish from my grandmother.' The Brins were no different from their fellow immigrants in that being Jewish was an ethnic, not a religious experience. 'We felt our Jewishness in different ways, not by keeping kosher or going to synagogue. It is genetic,' explains Michael. 'We were not very religious. My wife doesn’t eat on Yom Kippur; I do.' Genia interjects: 'We always have a Passover dinner. We have a seder. I have the recipe for gefilte fish from my grandmother.' (More at The Story of Sergey Brin )
Page has a Jewish mother but seems to be even less actively Jewish than Brin.