Several of the previous comments here have quoted a key, interesting fact from the submitted article: "Between 2-4% of requests can’t be served via our caches,

Several of the previous comments here have quoted a key, interesting fact from the submitted article: "Between 2-4% of requests can’t be served via our caches, and there are users who always need to be served by our main (uncached) application servers. This includes anyone who logs into an account, as they see a customized version." That's my experience when I view Wikipedia. I am a Wikipedian who has been editing fairly actively this year, and I almost always view Wikipedia as a logged-in Wikipedian. I see the Wikimedia Foundation tracks the relevant statistics very closely and has devoted a lot of thought to improving the experience of people editing Wikipedia pages. I can't say that I've noticed any particular improvement in speediness from where I edit, and I have definitely seen some EXTREMELY long lags in edits being committed just in the past month, but maybe things would have been much worse if the technical changes this year described in this interesting article had not been made. From where I sit at my keyboard, I still think the most important things to do to change the user experience for Wikipedia editors is to change the editing culture a lot more to emphasize collaboration in using reliable sources over edit-warring around fine points of Wikipedia tradition from the first decade of Wikipedia. But maybe I feel that way because I have worked as an editor in governmental, commercial, and academic editorial offices, so I've seen how grown-ups do editing. I think the Wikimedia Foundation is working on the issue of editing culture on Wikipedia too, but fixing that will be harder than fixing the technological problems of editing a huge wiki at scale. Human behavior is usually a tougher problem to solve than the scalability of software. By the way, the article illustrates the role for-profit business corporations like Facebook have in raising technical standards for everybody through direct assistance to nonprofit organizations running large websites like the Wikimedia Foundation. That's a win-win for all of us users.