Your sentence "do you know of any FANG which is happy to hire across international border and work with employees running their own company" implies a B2B relat

Your sentence "do you know of any FANG which is happy to hire across international border and work with employees running their own company" implies a B2B relationship. That is the company pay by an invoice from your company, this is not an employer-employee relationship. I have known people working like that in SE Asia but not a FANG in Australia. Companies cannot employ someone in most countries where they don't have a registered office due to legal reason. There are corporation laws, employment laws, tax laws to consider.