tips on hiring a freelancer online to do the ethereum smart contract and the minting website

I am hiring a freelancer to do my nft smart contract on ethereum and the website that will have the front end minting option. I want to make sure that I don't get ripped off (meaning they don't take all my funds after we launch) so I wanted to know what do I need to make sure I need to have the ownership of after he finished everything. I know I will need to have the smart contract ownership however I wanted to know what else I need for example website ownership etc etc