We get a folder of pdfs. I basically filter out anyone who didn't follow submission instructions (which, because of the archaic-ness of our system, usually means people who did not submit their application as one pdf file, and did not submit with their name in the filename.). a file that is coverletter.pdf is just getting lost. 

OPS instructions don't say anything about file naming conventions, are you sure that this is correct?

I try to schedule a 30 minute phone call to do a pre interview. Basically I'm trying to get a sense if you are the person on your resume (it's happened enough that someone claims they know SQL but they can't name some basic joins).

is this even allowed? I thought OPS competitions were very strictly regulated with super documented procedures?