What is BigPipe and what does it mean for the future of Drupal Performance?
it allows us to break our web pages up in to logical blocks of content, called Pagelets, and pipeline the generation and render of these Pagelets. Looking at the home page, for example, think of the newsfeed as one Pagelet, the Suggestions box another, and the advertisement yet another. BigPipe not only reduces the TTL of our pages but also makes them seem even faster to users since seeing partial content earlier feels faster than seeing complete content a little bit later.