The author suggests using git. But be warned git doesn’t work well with iCloud Drive. I used to have hundreds of git repositories in my iCloud Drive. Periodically, doing a big commit would trigger my whole multi-hundred gigabyte iCloud Drive to resync with Apple’s servers. This would take a day to complete. I went through Apple support up to quite a high level to try to resolve it and they never did. Now I keep my git repositories outside of iCloud Drive. The trigger seems to be if you ever change hundreds of files at the same time in quick succession before the last set of big changes finished syncing.
For what it's worth, git also can fail in some pretty bizarre ways in Dropbox for much the same reasons. I've used git-remote-dropbox [1] in the past to use Dropbox as a git server.