Here is my interview exp (Chinese american):
1.Who is your employer?
2.Who is your end client?
3.What does your company do?
-->Gave details about my company.
4.Who is your vendor?
--> There are no Vendors in between. My employer is direct vendor for my client.(He wrote in a paper some thing like EMPLOYER==>CLIENT)
5.Can i have all the contract docs?
--> I gave him all my contract docs,PO,Client letter.
6.Can i have your I129
--> I gave him I129
He took all my contact docs, PO, Client letter,I129,I797,Passport and gave me the white form and told me that they need to do some additional processing.