I applied through a staffing agency. The process took 1 day. I interviewed at Data Connection in June 2009
Interview
Had an online skills test. It consisted mainly of knowledge based C questions, pointers, arrays, types of variables (auto, register etc). It also contained small code snippets asking for the output.
It's easy if you practice for this sort of thing. Unless you're using these weird C constructs only a daily basis, I recommend you read through K&R before taking the online test.
Interview questions [2]
Question 1
You're given C code snippets and asked to show what the output is. I don't remember the exact snippet examples, but it's fairly tricky pointer manipulations. Something along the lines of the code for memcpy function comes to mind.