By now, we have a fair idea about what a design pattern means and how it can affect the way we write our code. We've iterated the most famous design patterns out there, and we have outlined the main differences between them. We saw that in many cases, we could use Scala's features in order to make a pattern obsolete, simpler, or different to implement compared to the classical case for pure object-oriented languages. This book will show you how Scala makes it easier to write high-quality code.

Knowing what to look for when picking a design pattern is important, and you should already know what specific details to watch out for and how important specifications are.

Last but not least, we advise you to run the examples in this book, and we have provided some pointers that should make this really easy. In some cases, creating a complete solution using SBT or Maven might be too much hassle and something unnecessary, but we believe it is a good practice to follow. Additionally, the approaches we explained are used throughout the industry and will be beneficial outside the scope of this book.

In the next chapter, we will get straight to the practical part of this book, where we will look at traits and mixing compositions, what they are useful for, and how and when to use them.