Synchronization is automatic. It does not take up any of my time.

I have enough drive space to maintain backups going back several months, which protects against both file corruption (volume corruption is taken care of by redundancy) and mistaken deletion/modification. In any case, the files in question are mostly text or text-based, not binary formats, so corruption is less of a concern.

Code, specifically, is of course also kept in git repositories.

Backups to read-only media are a good idea, and I do them periodically as well (not blurays, though; DVDs or even CDs suffice, as the amount of truly critical data is not that large).