Testing third party code once embedded in a page, is often difficult and cumbersome. Verifying those elements are working properly (or even more basically, are not breaking the page) is difficult to get right. Clients will often not give you access to their page, or allow you to debug 'live', leaving scope for bugs to creep in.
So what is the right approach to take?
Nate is a software developer lead at Magnetic, an advertising firm in New York that focuses on Search Retargeting.
Formerly, he has worked at OMGPOP, Lehman Brothers, and his own startup Robot Recruit.
He has a dog named butters that accompanies him wherever he goes.
blog: dewful.com (not updated too often)