I initially spoke with representatives from A-B at a career fair at my university. After giving them my resume, I got a call back requesting a brief on-campus interview the following day. This seemed like more of a screening process and lasted about a half hour.
Less than a week later, I received an email requesting that I take an online screening test. This exam was incredibly simple, asking a range basic math/analytic and scheduling questions, as well as some reading comprehension kinds of questions. Pretty straightforward. As best I can tell, this was just filters for basic competency.
Following this exam, I was asked to take a followup test, which asked more personality/leadership style questions. Each of these exams took about 45 minutes to complete.
About a week later, I received an email requesting that I participate in what they call the TAP. This is a "telephone-based work simulation," which was pretty bizarre. You are given a packet of information and about an hour of time to come up with a fictitious brewing schedule. Then you explain the schedule via telephone to your simulated boss, who will proceed to yell at you.
After this demoralizing phone call, you then receive an additional packet of information, and must decide how to best convince an unruly technician (via telephone) to do his job, which he will whine about.
Your final telephonic task is to conduct a meeting with a couple of operators, who bicker with one another and have many complaints. You must sort through a pile of information and decide which memos to share. This 3rd phone call concluded my TAP experience.
At this point, I was asked to come on-site for a final interview. I was not told who I would be speaking to ahead of time, though, when I arrived I was given a schedule, which was immediately disregarded. I interviewed with 3 or 4 different teams, each discussion lasting about a half hour. For the most part, the interviewers seemed particularly unhappy to be present, which was a bit disconcerting. Each team had somewhat different interviewing techniques, but there was nothing out of the ordinary.
About 2 weeks later I received a form rejection letter. The whole process took around 2 months.