I currently have a website that has been recently completed. I'm contemplation using a freelance service such as SO for all future components. There is a considerable amount of work to be completed on-top of the existing infrastructure.
I've tried searching for an answer to this question, but it's so generic in terms that it's difficult.
My site is fairly complex using relational databases, MySQL, PHP, Javascript, JQuery, and Ajax.
I'm concerned about using a freelance worker on the site in regards to giving them admin access to the server and allowing them to access the existing databases. Is there a tried and true way to handle / manage this? I'm open to allowing it, but what safety precautions and other ideas do you have to prevent mischief?