The standard
Highly available production infrastructure is normal now. Backup infrastructure much less so, even though in a real incident it is the only one that still counts. It should be the equal of the primary: secure, fast, solid, scalable.
3-2-1-1-0
Three copies, on two kinds of media, one of them off site, one of them immutable, and zero errors on the restore test. The last two digits are the ones missing in practice.
Immutable is the answer to ransomware. A backup an attacker can delete with the same credentials that reach production is not a backup at the moment it matters.
Zero means tested. A backup whose restore has never been exercised is an assumption.
How we build it
To your requirements, with products that complement each other rather than overlap. For all the engineering behind it, daily operation has to stay simple, because a procedure that is tedious day to day gets worked around.