Google employees at the Mountain View, Calif., headq in Silicon Valley were born overseas. More Photos »

Do We Need Foreign Technology Workers?

The question coeers around a crowded conference table at Google. They have gathered to discuss how to build easy-to-use maps that could turn hundreds of millions of mobile phones into digital Sherpas — guiding travelers to businesses, restaurants and landmarks.

“His plane gets in at 9:30,” the group’s manager responds.

Google is based here in Silicon Valley. But Sanjay G. Mavinkurve, one of the key engineers on this project, is not.

Mr. Mavinkurve, a 28-year-old Indian immigrant who helped lay the foundation for Facebook while a student at Harvard, instead works out of a Google sales office in Toronto, a lone engineer among marketers.