Personally, I didn't notice the outage. It was quickly fixed, and websites were back online within an hour. Some sites didn't even go dark, I gather: instead, they just slowed down. The cause? A software bug in a systems update at a company called Fastly ( NYSE: FSLY ), which hosts web content for a truly staggering roster of some of the world's biggest online businesses. Take a look at the customer case studies on Fastly's website: a more impressive list of the brightest and best would be difficult to imagine.