I would not know about the interview process. I got a rejection letter in my email 30 minutes before i actually received an email confirming my resume and application had been received. Apparently they do not use people to look at resumes and only use computer programs.
I've applied for a couple of jobs here, as has my colleague and neither of us have ever had any sort of confirmation or 'thanks but no thanks email'.
They've been added to my blacklist of companies not to work for.
Even a template email is better than being ignored entirely, which is exactly what you're doing. Would you do it your customers? No. So why do it to people who really want to work with/for you?