Why E-Commerce Applications Should Embrace Cloud?

Today is day before Thanksgiving and Express (a clothing brand) just sent an email to all its members about its exciting sale offer (50% of entire items). This is their once chance of the year to bring in shoppers to make good revenue. If only they could keep the site up..... If I was part of their engineering lead,  I would bring all engineers to the drawing table and rethink scalability and availability from ground up.