I am trying to create an ISO file for Debian Buster installations, but I need it to be independent of internet connection (standalone) to complete the installation.
I also don't care about desktop version or even existence of desktop environment. A terminal is fine.
To help you formulate any answers, I have some experience as a power-user with Unix (filesystem structure, bash etc) and my internet connectivity is good so downloading anything (Debian DVDs, tools or whatever else) is not a problem.
Also, the ISO file must fit in a 16 Gb flash drive and finish installation (even with minimum packages) without internet connection, there are no other restrictions.