Transloadit offers media upload, modification, and storage as a service for developers who need that functionality (or, as Transloadit's homepage puts it, "geeks who run web or mobile applications") but don't want to worry about it themselves. There aren't too many moving parts to it, but they're ones a lot of applications make use of. The Transloadit API's main functions include: file upload, image resizing, video file encoding, image thumbnail creations, and file storage on Amazon S3.
Filestack has announced that the Filestack v3 API has been extended to include access to Intelligent Ingestion, a new technology that ensures file uploads are successfully completed even under tough network conditions. The company also released updated SDKs for iOS, Android, Python, PHP, and Ruby.