What KYC checks does Xoom perform on senders and recipients across different countries?

For Xoom any money being sent, has already been KYC screened as you have to use a Credit Card or Bank Account to fund the money to remit. The credit card company or the bank has already done a KYC to you. With Xoom, they are merely confirming the same.

Xoom cannot do the beneficiary side KYC as that would be the responsibility of the beneficiary bank.

Xoom does however have to comply with OFAC and SAR checks.