This simple Flash animation lived on the homepage of the Amex "My Life My Card" website. I had to follow a fairly rigid template, as the SWF was loaded dynamically into their pre-existing Flash application.
But to be honest, the hardest part of any job like this isn't making the animation. It's getting all the necessary information, documentation, and code samples you need from the client and their vendors so you can be sure that you're actually delivering them something that works.
I was responsible for all the animations and actionscript.. and making sure that it worked.