I recently came across a good article titled Scaling Lessons Learned at Dropbox. In it, the author, Rajiv Eranki (the second engineer hired at Dropbox), explains how they successfully managed to scale Dropbox from 4,000 users to 40 million. It’s a very interesting read, presenting many good, concrete solutions to a problem that most of us are never fortunate enough to have. A bit technical at times, yes, but worth the read.