The phone screen started out pretty informally. After a few questions about what I had done in recent jobs, he asked if I wanted to go ahead with more "technical" questions, or to have him send me the description for an SRE (Site Reliability Engineer) job. Since I know a fair amount of what the SREs do, I figured what the heck, can't really prepare for this stuff anyway so we'll just see what happens.
There were some questions I just didn't remember the answers to, such as "What system call gives all the information about an inode?" and "What are the fields in an inode?" Since it has been nearly 20 years since I've done anything involving (kernel) file system development, I don't have that information on the tip of my tongue. (However, it occurred to me after the interview that he was actually asking for the information returned from a stat() system call – I just wish he had phrased the questions a bit differently.) He asked if I knew the worst case runtime for quicksort, which I did not remember, but I did give the average case, and said that I could get the information from the wikipedia page on sorting in two seconds, but he said no, He asked me to estimate what the decimal value of 224 was without using a calculator, and I made a careless mistake, but from doing a lot of talking which aggravated my throat (I'm getting over a cold), I started coughing while speaking, which threw my train of thought off somewhat. However, I did answer a number of other questions correctly involving some other system calls, the TCP three-way handshake (this seems to come up fairly often), and a few other things. I also got the "rate yourself 1-10 on the following languages, OSes, etc." question, and decided to be a little less conservative, and give myself an 8 on C and Perl (since those where on the level of "has done significant development work" or "has contributed to a project" but not "has textbook knowledge" (and may have actually written a textbook). (Since I have recently done a little bit of Python programming and testing related to dance competition scoring, I decided to give myself a 2 – we'll see how that goes.)
The good news is I did well enough to make it to the next round. Next week, I'll have a more in-depth technical interview. In the meantime, I have a lot of material to review.
I still don't like these types of interviews, and probably never will. They don't really show my best qualities, and I always feel stressed. However, I am not alone, and in fact, some people who give these types of interviews realize that they don't really test job competence. I wrote about this some on my FB wall, but will go into it in more detail here when I have more time. (It relates to things I have written in the past about not being able to "perfectly prepare" for things, and paying opportunity costs for spending (too much) time on some things at the expense of others.)