Pre-onsite was pretty standard with a couple of phone loops. The on-site was where things got rough.
Grueling 9 hr loop with almost no breaks (single half hour break for lunch). Support, code, architecture, management and more were covered, some better than others.
Support - Pretty standard "sev 0 outage, what do you do?"
Code - This seemed sloppy. Rather than anything real world applicable, I felt like I was back in college taking a data structures and algorithms test.
Architecture - Pretty standard, "Design a system to a spec" type stuff.
Management - This one the interesting one. There was a standard interview over management concepts, but there was also a mock interview where you're handed a resume and have to wing an interview for that candidate on the spot, then do a post-interview debrief with *your* interviewers.
Some of the content here seemed very value add, but it was drowned out by several sloppy technical pieces in the course of the long day. By the end I wasn't even sure I wanted the job, if the work environment is anything like their interviews.
Also, while some of the interviewers seemed genuinely interested in the process and in me, others seemed put out to even be there, or overtly hostile. Not people I'd feel comfortable getting a fair shake from afterward.