Our users love Dropbox for many reasons, sync performance being chief among them. We’re going to look at a recent performance improvement called Streaming Sync which can improve sync latency by up to 2x. Prior to Streaming Sync, file synchronization was partitioned into two phases: upload and download. The entire file must be uploaded to our servers and committed to our databases before any other
![Streaming File Synchronization](https://cdn-ak-scissors.b.st-hatena.com/image/square/129ad22ac653f2921cbd1b397ce9de9cf335526a/height=288;version=1;width=512/https%3A%2F%2Faem.dropbox.com%2Fcms%2Fcontent%2Fdam%2Fdropbox%2Ftech-blog%2Fen-us%2Finfrastructure%2Fdropbox-tech-infrastructure-1-1200-628.png)