In Italy the procedures for vote counting are fairly complex and involve several persons.
Each territory is subdivided in so called "sezioni elettorali" (electoral sections), which may be a subset of a neighborhood in big cities, or big country areas. Each citizen is registered in one electoral section and each section, during elections, is assigned a group of people called "ufficio elettorale di sezione" (section electoral office).
The people comprising the sections electoral offices are common citizens taken from special lists to which the subscription is voluntary. Subscription is subjected to some requirements to avoid conflicts of interests and to prevent people with criminal records to subscribe.
The exact composition of the electoral offices may vary with the kind of elections, but for the last political elections of 25 September 2022 every section electoral office was composed by (document in Italian):
- 1 president
- 1 secretary
- 4 counters
The principal duties of these offices are to regulate the voting operations during the actual voting session and then, after voting has closed, to count the votes.
The manual I linked to describes all the rules and procedures for the electoral offices. In particular, the counting of votes must be carried out in this fashion (described starting from p.102 - I simplify a bit, since the rules are a bit convoluted):
a. A first counter, randomly chosen, takes a voting card out of the
ballot box, unfolds the card and pass it to the president.
b. The president speaks loudly the expressed vote.
c. The president then pass the card to another counter.
d. This latter counter takes note of the result of the vote on a
e. At the same time the secretary also speaks loudly the result of the
vote and records it on a register.
f. A third counter takes the card and stores it in another box.
And in another part of that document it is stated that during the counting all the members of the office must be present. If one member has to go to the bathroom, for example, the counting must stop.
Moreover, it is also stated that the voting cards can be handled exclusively by the members of the office.
This last requirement is important, because during these counting operations, which are carried out in a closed room in which the access is restricted and which is guarded outside by armed policemen, there may be other authorized people present, the most prominent of which are the so called "rappresentanti di lista" (list representatives).
These are nominated by the parties and have the right of being present during the counting to check the impartiality of the procedure. Usually list representatives are not unique for a single office (for lack of personnel), and they often are responsible for many different electoral sections, so they come and go and take turns checking different offices at different times.
As you can see, it is quite a complicated mechanism. Subverting it would require that several different people, randomly chosen, would be accomplices in an electoral fraud. You would need at the very least the president, the secretary and two counters to be in cahoot, assuming the other two counters and the list representatives were almost sleeping!
Note that there are two independent registrations, and these are checked first by the local electoral office (usually one for every city), and then also rechecked by a jurisdictional court. So any mismatch could lead to a recount.
In Italy we have a record of Mafia "driven" electoral frauds, especially in southern regions, but they were usually carried out with systems that bypassed the section electoral office. It is much more simple to intimidate people to vote for someone than to bribe a whole bunch of random people. And there are/were tricks to make sure electors did actually vote for the "Mafia-supported" candidate (in recent times a photo of the electoral card taken during voting would suffice, although officially smartphones are not permitted in the voting cabins).