Every interview is different, because every candidate is different and the saying “man sanctifies the place” works perfectly.
Of course, the recruiter often has predefined questions to save time and make the interview more consistent. But it is also true that it is sometimes good to be spontaneous, creative and to test certain skills of the candidate “at the moment”.
As a candidate, it is good to prepare for the interview, do not rely on the reaction of the moment. Usually, the “soft” skills that are tested by the recruiter refer to: the ability to adapt, whether or not you fit the organizational culture of the employer, if you have the ability to work in a team, leadership, development potential and if you know how to prioritize tasks.