The book is about a future world where the majority of people live in squalor but the heroine lives on a beautiful island protected by a bubble. The inhabitants are able to protect their lifestyle because the heroine and her aunt (?) have exceptional computing skills and are able to enter the deep digital world and develop world reknowned cyber-security packages for high prices. The book is heavy on jewish mystique, legend and history. I think it was called 'Mirror of Glass' but cannot find it anywhere under that title. I loved it and the storyline becomes more and more real as time goes by!
I think this is He, She and It by Marge Piercy, 1991. (published under the title Body of Glass outside the USA)
the majority of people live in squalor
"...in the near future of the year 2059. At that time, the economic and political power is held by few multis— huge multi-national enterprises with their own social hierarchy that have produced an affluent society. The main part of the population, however, lives in the glop outside of the multis' enclaves within an environment that has mainly been destroyed."
the heroine and her aunt (?) have exceptional computing skills
"When Malkah (Shira's grandmother) is working on a chimaera (security software) to protect the city from online attack..."
"When the protagonist Shira loses custody of her son Ari to her ex-husband Josh, she returns from her multi Yakamura-Stichen (Y-S) to her hometown Tikva (Hope in Hebrew) - a Jewish freetown. There, she starts working on the socialization of the cyborg Yod (the tenth letter in Hebrew and a symbol for God in Kabbalah), who has been created illegally by Avram to protect the city."
The book is heavy on jewish mystique, legend and history
"The main plot is interwoven with a story Malkah tells Yod that deals with Rabbi Judah Loew who Malkah depicts as her ancestor living in the ghetto of Prague around 1600. To protect the Jewish community from the Christian mob, Loew uses the knowledge of Kabbalah to create the golem Joseph from clay."