Invent and Wander: The Collected Writings of Jeff Bezos

by Jeff Bezos

One example is Whispersync, our Kindle service designed to ensure that everywhere you go, no matter what devices you have with you, you can access your reading library and all of your highlights, notes, and bookmarks, all in sync across your Kindle devices and mobile apps. The technical challenge is making this a reality for millions of Kindle owners, with hundreds of millions of books, and hundreds of device types, living in over one hundred countries around the world—at 24/7 reliability. At the heart of Whispersync is an eventually consistent replicated data store, with application defined conflict resolution that must and can deal with device isolation lasting weeks or longer. As a Kindle customer, of course, we hide all this technology from you. So when you open your Kindle, it’s in sync and on the right page. To paraphrase Arthur C. Clarke, like any sufficiently advanced technology, it’s indistinguishable from magic.