My interview was a full day. I met with the manager of the position I was applying for, who gave me a tour of the building and described the company, the products, and what was involved in the job.
I met separately with a few different groups of people, including the other employees in the same role. This was an open discussion of what the job entails, what they like, what the challenges are, what they are looking for in that position. This was the most beneficial part for me because it showed what the culture and group dynamic was like.
There were no formal questions, just a discussion of what I did at my previous job and in school. I was surprised and a little relieved there was very little technical content to the interview. For an Applications position, they don't expect you to come in with a complete understanding of the techniques, but they are looking for some scientific background and mainly aptitude and willingness to learn.
For this position, you're asked to give a technical presentation to a group of Apps engineers and managers. Depending on the position, there may be other managers watching by video from other locations. You can present on anything, like the research you did in grad school, but it should have some relationship to one of the techniques TA does. This is an important part of the interview because giving technical presentations is one of the main job responsibilities.