It depends what I’m backing up and where it’s backing up to.

I do local/lan backups at a much higher rate because there’s more bandwidth to spare and effectively free storage. So for those as often as every 10 mins if there are changes to back up.

For less critical things and/or cloud backups I have a less frequent schedule as losing more time on those is less critical and it costs more to store on the cloud.

I use Kopia for backups on all my servers and desktop/laptop.

I’ve been very happy with it, it’s FOSS and it saved my ass when Windows Update corrupted my bitlocker disk