I don't think you're skipping the interview process (that's quite rare), but you're not worried about using it to prove your competence and look for dark secret

I don't think you're skipping the interview process (that's quite rare), but you're not worried about using it to prove your competence and look for dark secrets in the company. If a friend has told you the company is on the level, and told the company you're on the level, the interview becomes much more sociable and low stress. You're each confirming what you already know and looking for a good fit, rather than being suspiciously analyzing one another.