Quite a dynamic web shop, fully manageable.
Although the site itself is rather big than complex, there was a challenge on implementing the payment gateway (MercadoPago), since the provider had not much support on implementations at the time, and the client wanted the payment process to be embedded in the site.
So we prepared a fresh new mate (gaucho’s beverage, think on coffee if you don’t know it) and run some tests to have a comprehensive view of the gateway’s API. Then we coded the implementation, which we did as a module that later published to the programmer community to help newcomers.