The common pattern is that the off-shoring company will deploy workers on site for a year to do knowledge transfer and documentation of existing processes so that they can be moved off shore.

Usually (but not always) these workers come into the US on a H-1B visa.

I have not seen this in my career. Its usually PE or cost cutting causes US roles to be split into mult off shore roles because the pay per engineer is less outside the US. Like everything else the talent is a bell curve.

Wow! Didn't now that, thanks for sharing. They've exploited this well, even after tons analysis - I'm still stumbling upon new things.