The journey of improving coding skills continues even after learning programming. The key question How can one write code professionally while addressing critical concerns such as code maintainability, code re-usability, security issues, and memory leaks? This book focuses on real-world code examples, aiming to avoid unnecessary, boring, extended theoretical discussions. Instead, it goes straight to the point in coding and offers improvements with clear explanations.Any building is eventually finished, but successful software is never truly finished. New features need to be built, causing the code base to grow over time, and concerns about maintainability grow with it if programmers don't pay serious attention to it.If you asked an expert and a junior programmer to write code for a specific program, you would realize that the expert accomplishes the goal with significantly less code than the junior programmer. Every extra line of code written unnecessarily creates more issues in terms of maintainability, opening the doors to hacking and security vulnerabilities.The problem with coding is not that poorly written code doesn't work; the real problem is that it does. Therefore, it can be challenging for an inexperienced programmer to realize what a better version could be.In this book, I will provide you with common mistakes through different pieces of code that function correctly, but I will also explain why it is crucial to avoid that kind of coding, even though it works.Before diving into the chapters, let's highlight a few code issues to help you determine whether this book will benefit you. The code examples provide a preview of this book's approach to assist you in improving your Java coding. This book systematically addresses issues in the following Presenting common code mistakes through a simple piece of code.Running the code to reveal unexpected outcomes.Explain the case and provide code improvements.This approach ensures you understand how to manage similar code challenges in your programming work.