Once of the most common uses of the Dropbox API is to upload files to Dropbox. If you only need to upload one small file, you can do so with one Dropbox API call, but when you need to upload a large amount of larger files, and you need to do so very quickly, things can get more complicated. In that case, you'll need to consider things like lock contention and parallelization.
For tips on how to manage these considerations and upload file data fast, check out our updated Performance Guide. We've added some information on using new functionality on the Dropbox API that can help you upload file data fast, by starting multiple upload sessions in batches, and by further parallelizing upload session requests.
Also, check out this new code sample that takes advantage of these features to upload file data as quickly as possible. You can tune the thread count parameters to match however much parallel traffic your network connection can handle.