My age, work experience and expertise are similar to the OP's. I just interviewed with Google, FB and Amazon, and found myself nodding my head at several points in the article.
Something I learned after the whole process was that people apparently take a month or two to prepare intensively and specifically for interviews with these 3 companies. Luckily I came out of the ordeal with an offer, but I wish I had known that tidbit before.
Perhaps this is because big companies are interested in loyal employees in the first place, so they prefer candidates which can learn certain not-so-practical pieces of knowledge just for the sake of passing the interview for that company.
Give me a shout when you're in bootcamp (my unixname is 'nbm'), especially if you're interested in working in infra and want help finding out about and choosing between teams.
Something I learned after the whole process was that people apparently take a month or two to prepare intensively and specifically for interviews with these 3 companies. Luckily I came out of the ordeal with an offer, but I wish I had known that tidbit before.