I went to App Academy a few years back. I ended up taking a software development job at just about the salary they advertised, spent over a year there, and then moved on to one of Amazon/Facebook/Google/Microsoft.
I don't think I did anything special. At some point a recruiter from one of those companies messaged me on LinkedIn, then I spent a couple of weeks preparing with Cracking the Coding Interview. I'm not a senior engineer - I interviewed for a mid level role but got a junior level offer. Probably didn't do well enough on the systems design questions.