SFTPGo allows to securely share your files over SFTP and optionally FTP/S and WebDAV too.Several storage backends are supported and they are configurable per user, so you can serve a local directory for a user and an S3 bucket (or part of it) for another one.SFTPGo also supports virtual folders, a virtual folder can use any of the supported storage backends. So you can have, for example, an S3 user that exposes a GCS bucket (or part of it) on a specified path and an encrypted local filesystem on another one.Virtual folders can be private or shared among multiple users, for shared virtual folders you can define different quota limits for each user.