Multiple. Locally I have Timeshift doing btrfs snapshots every so often. This is mostly to roll back to a snapshot if something breaks. I've never had to use it (and probably should).

I use Pika backup every once in a while for a local backup to an external drive. Mostly because it's easy to restore quickly.

I have duplicacy doing backups to a cloud provider. I used to use duplicati for this, and it was fine - although I didn't like that it seems to be forever in beta. I like that duplicacy can do deduplication between backups of different machines which most other solutions I've seen cannot. I like its selection of cloud providers vs Borg/Vorta and some others.