I have only done internal interviews for past 10 years. Usually three people are conducting the interview. Each question has about 3 things they are looking for. Situation/Problem?How was it handled? Final Outcome? I have had 19 interviews internally with this company. I know what to expect in general so I prepare. Sometimes there will be a phone, one-on-one, panel, or even multiple interviews. Preparation is key. The scheduled time for the interview will vary depending on the position in which you are interviewing. I've had interviews last for twenty minutes up to an hour. Expect a follow-up interview. The interview process is not over just because you left the room. All eyes will be on you up until the decision has been made. Important to know what you are applying for and be prepared for answering questions specific to the functions of the job.