For me personally, I am still mystified by how subjective interviews like System Design/Behavioral are graded. E.g. if asked to design a large scale distributed system like Uber what would be the pass/fail criteria when calibration of responses is done w.r.t. YOE (5/10/15)? What would indicate that such and such is a good response for someone at Principal level but not so for someone who is at Senior level or vice versa.