Almost every job I apply to, when I do get a response, I get a form letter: "Blah blah blah, we're impressed by your skills and experience, but we're going to concentrate on other candidates who match our needs more closely right now. kthxbye."
Never apply online. You are lucky enough to be getting a form letter for your trouble; most people just never hear anything, if they go that route.
I play the numbers. 100 applications leads to about 10 summary rejections and about 3 screening phone calls. Maybe 1000 applications to get to the second interview. It is an extremely inefficient process, but I have no industry contacts, and my part-time work frequently overlaps the industry's party times.
A few of the companies make me jump through hoops, the coding challenges, before sending me the same form letter.
OK, here's the reality of things. As an autodidact, you are probably not very qualified to work on a team, because you lack the proper vocabulary to communicate with your team members. This will come through in an in-person interview (really, the only kind anyone should consider, unless they are about to graduate, and take a phone interview instead).
The way it will come through is that you will perhaps know how to solve a problem using the computer, and you might even write the correct code on the whiteboard, but you won't talk about "Big 'O' notation" (algorithmic time order complexity) correctly, you'll probably think "everything is a linked list" or "everything is a btree", and you won't be able to name algorithms, and you won't be able to answer questions like "Why did you use a bubble sort, rather than a quicksort? Why didn't you do an insertion sort when you were building your data structure?".
Prejudice much? I did take algorithms in college, and I read algorithms papers. So far, only 1 company got as far as discussing the algorithm, and they were impressed. But they're busy doing a death march, trying to get a particularly complex product into the market, and in the end they were spooked by the lack of "qualifications." That was 1 month of stringing me along for nothing.
If you insist on this (non-degreed) route as an autodidact, my advice is to get the Knuth Algoriths books, and Sedgewick C++ algorithms book, and several other books that include discussions on "Big O", and learn the vocabulary so that you'll be prepared for your next interview.
Yes, well, I already have a bookshelf full of books and scientific papers to read. Sedgewick also has a very interesting MOOC on algorithms (that doesn't give you a qualification). It's just impossible to concentrate on studying when I'm in the wrong level of Maslow's Hierarchy.
I don't need more books. I need money.
I suspect that I will have to start my own company, just to create my own qualifications. This job market sucks.
Starting your own company will solve your employment problem.
Actually, it might not, because I don't have any ideas right now that would lead to money, except for some ideas that would require me to immediately spend money that I don't have. That's a downside of working at a charity-type non-profit: You tend to look for solutions that don't involve money. There's not much difference between self-employed with no revenue, and unemployed.