http://3oamv2de6ooacy72hv3ulym3i3vvlprlkqas7hhzo4pu5nyxnji37zad.onion/blogs/that-is-not-how-programmers-work
The thing about software development is that, the way we program changes over time, so the older a project is, the messier the code is. Another type of complex and messy code you encounter is when it is written by a young graduate, or by a person new to the language or framework.