Clean Code: A Handbook of Agile Software Craftsmanship

Bad code may work, but it will hinder the development of the project and the development company, requiring additional resources for maintenance and "taming".
What should code be like? This book is full of real examples that allow you to look... at code from various perspectives: top-down, bottom-up, and even from the inside. You will learn a lot about code. Moreover, you will learn to distinguish good code from bad, understand how to write good code, and how to transform bad code into good.

The book consists of three parts. First, you will become familiar with the principles, patterns, and techniques for writing clean code. Then you will move on to practical scenarios with increasing complexity—exercises in code cleaning or transforming problematic code into less problematic. Only after that will you move on to the most important part—the concentrated expression of the essence of this book—a set of heuristic rules and "code smells." It is this knowledge base that describes the thinking process while reading, writing, and cleaning code.