In general, I've heard that new hires typically get a year (at an established company - YMMV if you're going to a tiny company) to pick up what they're doing. After that, if you don't get it, you're probably getting fired if you don't quit first.
I'm using Udemy, which has some great teachers (and some bad ones), and the particular program/instructor is reportedly very good. I'm not expecting to do this and be ready, and I'm definitely not expecting to work for Google or Facebook, or even Boeing. I'm expecting to do this, do at least four additional courses, see what I can do in the meantime in terms of gaining creating a portfolio, and hopefully making a switch before I turn 41. I don't turn 40 until September, so I'm giving myself over a year and a half, and that's just a goal. I'm not going to kill myself if I spend 5 years working my current job before I can get a job somewhere else. Heck, at that point I'll probably be in a management position, if things continue to go the way they have been.
From everything I've read, you have to be very special and very lucky to get a job soon after completing a boot camp, and a sizable amount of people are going 6+ months or giving up. I'm not spending $20k on it, so I'm not as afraid of failure, but I'm also aware that my skillset is already more advanced than a lot of people, I'm just caught in the middle. I know too much to be a beginner, but not enough to be a professional. I can speak knowledgeably to my friends who are web/software developers, and I can read and make sense of a lot of code, but I can't write it, and I'm not dedicated enough to do it on myself without a formal program of some type. And I've been taking college courses, but sitting through 2 semesters of Microsoft Office, two semesters of HTML, a semester of CSS, and a bunch of other stuff I already know before I get to take a single class where I'll learn something is frustrating. It's easy, but it also feels wasteful to spend money to learn skills that I already have. Maybe it wouldn't be so bad in person, where I could help classmates, but doing it online is painful.