Here we are at the end of our journey through the Scala design patterns. As you already know, design patterns exist in order to cope with a certain limitation of a language. They also help us to structure our code in a way that makes it easy to change, use, test, and maintain. Scala is an extremely rich language, and we focused on some of its features, which make it capable of achieving things, which other languages might not be able to do without any extra effort and knowledge.

We looked at the different Gang of Four design patterns from the point of view of Scala—creational, structural, and behavioral design patterns. We saw that some of them are not even applicable in functional languages and that others can be approached differently. We also saw that some design patterns still remain valid and knowing them is really important for any developer.

We can't talk about Scala without dealing with concepts such as monoids and monads. At first, they could be pretty scary and abstract and...