I applied through a posting on my college's career website. First thing was an informal phone interview from a recruiter - this came with no warning. That went well - it was mostly informational (as in, them describing the position and organization to me). Then a day and time was set up for an in person interview. This lasted several hours. First, I took a basic math test. Then I met with two NSS managers (2:1). Normal, basic interview questions. Then came some time on the floor (about 15-20 minutes) with someone currently working the position - make sure you ask them lots of questions! Use this time to get to know the position. Then I had another interview with a different NSS manager. Finally, I got called back in to interview with a senior manager. (After this was the drug test.)