We started reviewing software projects of other companies, just a few weeks ago and our first finding is that programmers don't pay attention to anything aside from the code they write. They don't have build automation, unit testing, static analysis, continuous integration, test coverage control, database versioning, and many other things which are supposed to keep the code together. It seems that this is happening because of the lack of knowledge and experience.
The video is here: https://youtu.be/keGVpncTn4Q