mineistaken

Ok, so lets say you need some site done, example, classified site. You go to freelancer sites, pick a programmer and get it done.
Besides checking if every feature works, how do you know if programmer did a good job?
I am thinking that programmers can send you poorly written code and you (as a regular Joe) would not have idea about that. And you could even leave perfect feedback for programmer not knowing that programmers was actually bad.