[MichaelCrawford]

Cisco had a written test in which I was asked to debug a C++ program that had thirty lines or so of source.

Note that I did this with paper and a ballpoint pen - no computer.

That same test also had me reverse-engineer a network protocol packet, given a hex dump.

I have only had one other written test that I can recall. With that one I was given the assembly instruction architecture for a hypothetical CPU, then the source to a program, with the problem being for me to write down what the output of the program was. It was a huge PITA, and took me several hours, due to multiply-nested loops, recursion and the like.

I didn't get an offer from Cisco, but I did at that other company. The owner never tells anyone how they did on the written test though, other than that you get a job offer or you don't.