In recent past (6 months or so), I spoke to few people who were hired by AmaFaceGooSoft companies. The rigor and hours that people are putting to get in to these (or similar) companies is astounding. There are numerous startup training people for interviews. The question of: Is it worth putting so much effort for an interview is a topic of another discussion. 20-25 hrs/week of preparation over 4-6 month period is very common.
From companies perspective, the bar for technical interviews has become very high. The actual job may not be hard to excel at. However, when the market is flooded with candidates acing this form of interviews, companies don't have to settle for "average" folks.
Given this context, you have one thing in your favor: time. At this stage, put your time to very good use. Practice, rigorous practice, will land you a decent paying job. Experienced people, employed people, people with families are at a severe disadvantage because "Time" for preparation is a luxury they don't have (including me).
Again, I am only providing you anecdotal evidence on how to ace these interviews.