Learn Finnish: Kenen digitaalinen varmuuskopio on löydettävissä täältä?

It is the passive present participle of löytää (to find), combined with the plural inessive ending (-issä). Literally, it translates to something like "in a state of being found". With the verb olla, it expresses availability: on löydettävissä means "is available to be found" or simply "can be found".

The English translation says "found here". Why does the Finnish sentence use täältä (from here) instead of täällä (here)?

In Finnish, verbs of finding, searching, and buying always require a "from" case (elative or ablative). You don't find something at a place, you find it from a place. Because löydettävissä is formed from löytää (to find), it inherits this rule, requiring the ablative täältä.

If the backup is the thing being found, why is digitaalinen varmuuskopio in the nominative case rather than an object case?

In this sentence structure, the main verb is on (is). The phrase on löydettävissä acts like a compound adjective describing the subject's state ("is findable"). Because it is simply the subject of the verb olla, digitaalinen varmuuskopio stays in the basic nominative case.

How is the word varmuuskopio formed?