I was surprised to discover that FTP (or SFTP) is not reliable. A couple of years ago, I discovered that there were mis-matches between files sent to a remote SFTP server using Perl’s `Net::SFTP` and the checksum that was sent after the complete set had been transmitted. The uploaded files were a few bytes smaller than they should have been.

I didn’t have the time/resources for a deep dive to determine the root cause of the problem so my work-around at the time was to use `stat` to compare file sizes of the local and uploaded file. If they didn’t match, the file was simply re-transmitted – and it always worked the second time. ¯\_(ツ)_/¯

> though it's nearly dead

There's still millions of ftp servers running the wild: https://www.shodan.io/search?query=ftp