After some phone calls and few video calls we had two meeting in presence. The selection is too hard for this kind of position but I think that it's own internal modus operandi. After few weeks of the last meeting and some phone calls from my side where every time they postpone the decision to go ahead at the end they decide to do not hiring a new person.

No matter how good you are, they don't need someone good at their job. they only need a person who can make slides for presentation. The candidate was selected way before the interview. They took the interview just to show it was a fair interview process. but the top most management has already selected someone unworthy.