Things like Facebook and Google are at a level of scale where they need to do things entirely differently form everyone else though. e.g. for most companies, you'll get better database performance with monotonic keys so that work is usually hitting the same pages. Once you reach a certain size (which very few companies/products do), you want the opposite so that none of your nodes get too hot/become a bottleneck. Unless you're at one of the largest companies, many of the things they do are the opposite of what you should be doing.