What to read in this case?

Question

Software design

I am writing a small desktop application, at the moment it has already been rewritten several times, cleaned of shit code and getting better, but I feel the moment when it will have to be expanded again and the situation will repeat itself. I ask for help, tell me the literature on the topic of designing small and medium-sized applications. Tired of rewriting the same thing, please recommend books, articles, videos on the topic of architecture. Get a job in the office and gain experience can not. The only source of experience is the Internet and books.
A little about my crutch in the world of code - the java language (due to the tasks that the application solves, jni and the c language will be added), at the moment the number of patterns is constantly growing, either are connected and most likely part of the code will be transferred to the web, the muzzle to javafx (a bunch all sorts of css styles, sometimes in the code sometimes in files), there is work with the database and file transfer via the Internet will be implemented.

Answer 1

read about mvc patterns, and better mvp.
read about solid principles. especially about the last dip.
read about tdd, it's especially useful to see an example of how it works.
write testable code. rewriting is okay to start with. otherwise how to understand that the architecture is not acceptable or unsuccessful. try to break the program into independent components. as a result, there will be less rewriting.
from books you can Martin R.S., Martin M. - Principles, patterns and methods of agile development in C # - 2011
from video for example https://www.youtube.com/watch?v=lDdJYid8NpE&t=432s
from articles https:/ /habrahabr.ru/post/276593/