I have never been paid to write code, and my formal CS education is limited to AP Computer Science, and a one-credit Java class in college. I wrote 20 years ago a backup script implementing Mike Rubel's insight <http://www.mikerubel.org/computers/rsync_snapshots/> about using `rsync` and hard links to create snapshots backups. It's basically my own version of `rsnapshot`. I have deployed it across several of my machines. Every so often I fix a bug or add a feature. Do I need to do it given `rsnapshot`'s existence? No. Is it fun to work on it? Yes.

(I've over the years restored individual files/directories often enough from the resulting backups to have reasonable confidence in the script's effectiveness, but of course one never knows for certain until the day everything gets zapped.)