Given how little most people involved in the interview process--on either side--particularly enjoy said process, it seems odd to highlight how much effort you'v

Given how little most people involved in the interview process--on either side--particularly enjoy said process, it seems odd to highlight how much effort you've put into prepping for it. And it really is like asking for the difficulty to get ratcheted up a level. If I tell you I'm really, really good at interviewing, you're going to take my word for it and adjust your own behavior accordingly. Even if that silly certificate just created an unconscious bias in the mind of your interviewer, with them expecting just a bit more from you, you're a bit worse off.