How to check the completion of a linux setup task?

Question

linux

The question arose of how cheaply and efficiently to check the performance of work by a freelancer.
The essence of the work is to set up a NAS file cleaner on linux using Nextcloud, with the system configured so that it meets all the nextcloud requirements for security (including SSL connection), speed and reliability, incl. redis, setting up apache, databases, etc. What to request from the executor, command line logs or something else? Or is it a separate job for which you need to hire a specialist to check the absence of backdoors, etc.?

Answer 1

And then hire another specialist to check the work of the first and second specialist, and then hire the fourth, and then leave for Kashchenko.

For this, technical support and a guarantee were invented, all this is prescribed in the service agreement. You not only rent the site, but also serve it for X months for Y money.

Answer 2

In order to check the work of someone, you yourself need to understand this no worse than the performer.