Ask HN: How do you protect against data corruption?

I backup religiously and keep versioned backups (of limited depth due to storage space). Recently a few blocks went bad on my SSD and some files corrupted. I didn't pick up on this until I next went to open the files, by which time the bad version was all that my backups contained. How should I ensure that backed up files aren't corrupt, and that I detect file corruption when it happens? I'm looking for solutions for all platforms (Windows, OSX, Linux) as running them all.