Interviews vary WILDLY depending on organization, and I'd hazard to say the bigger the company and/or flight department, the more structured it will be.
During my interview, it was strictly personality-based from the owner, with the exception of being asked to brief a single ILS approach from the Chief Pilot and pointed questions about my background as an ALPA volunteer. It helped that due to STRONG networking I had the owner in my corner and the interview was more of a formality. Total time, about an hour.
A few months later when I got to hire a pilot, his interview from the boss was strictly "Tell me about yourself" and "Why do you want to work here". More time was spent talking about our operation than it was asking the candidate questions...but again, I knew the candidate via networking so personality issues with me were already resolved. Total time for his interview was about 35 minutes.
I know of a local Fortune 500 company with a multiple-aircraft fleet whose hiring process takes more than a month and includes a screening of resumes by current pilots, multiple interviews which 'cut' candidates each time, a sim evaluation for the final candidates, and finally those selected by department management must have a final interview with senior company management and be approved.