Job posts are usually submitted internally and externally. Regardless of current position, each employee is interviewed. I know that is to avoid any "hard-feeling" between coworkers. The job post stays open for one week, and interviews are conducted the following two weeks.
There were the usual "interview" questions that the hiring manager printed out, but it felt like the most important thing in the interview was how we "vibe'd" off of each other. I thought it went very well, and was confident that i would at least be considered for the position.