People don't get that technical skills are not enough to get good at technical interviews. It even sounds funny because these are TECHNICAL interviews. But Interviewing is a skill by itself: how to communicate, how to walk another person through your thoughts when you haven't reached an answer yet or might be lost, how to address non-obvious challenges while explaining your solution strategy and how to do all of that under pressure. All of this goes above and beyond knowing the answer... Practicing is key. Many of my friends with strong backgrounds failed on most of their interviews, but after learning how to do interviewing they were able to land almost every job they wanted.