for my personal backups i've used for more than a decade http://rsnapshot.org (it's a simple perl script). it's time to upgrade, so i'm moving to restic https://restic.net/ (but rsnapshot is still running).

features:

cryptography
https://blog.filippo.io/restic-cryptography/

data model
https://restic.readthedocs.io/en/v0.7.3/references.html

dedup
https://restic.readthedocs.io/en/v0.7.3/references.html#backups-and-deduplication

http rest backend
https://restic.readthedocs.io/en/v0.7.3/rest_backend.html
https://jpmens.net/2017/08/22/my-backup-software-of-choice-restic/