Skip to main content
March 30, 2022

What Is Kotlin and What Is It Used For?

If you have heard of Kotlin it’s because you are interested in Android development. Kotlin is one of the programming languages that has gained the most momentum over the last 5 years. In fact, over 80% of the 1000 most popular Android apps currently use Kotlin.

What you may not know about Kotlin is that is not only used for Android app development but has also been making its way into other sectors. Keep reading if you want to know more about Kotlin and the advantages of using this programming language.

What is Kotlin?

Kotlin is an open-source programming language created by JetBrains that has become popular because it can be used to program Android applications.

This language is statically typed since it can be developed on top of JVM or JavaScript; or since a few months ago, even without the need for either of them, since it is being developed in parallel in native with LLVM. Thanks to that, it is fully interoperable with Java code, which allows us to migrate our projects in a gradual way.

Kotlin’s History

The history of Kotlin dates back to 2010, when JetBrains, the famous company that created several of the most widely used IDEs such as IntelliJ or WebStorm, published the first version of this programming language.

In 2012 it became open-source, so it is a relatively young programming system, although it has become fundamental to understand the evolution of applications for mobile devices.

In fact, it was not very popular in its first five years of life, and it was not until 2017 when Google announced that it would support Kotlin, that it finally began to gain popularity among app developers. Since then, its adoption has been on the rise, and it has become the preferred choice of 72% of developers when developing for Android.

Kotlin’s Features and Benefits

Kotlin stands out for the advantages it has over Java (we will talk in-depth a little later) when developing mobile applications, in addition to presenting features such as simplifying the reading of the code and its development.

These are some of the advantages and features of Kotlin:

Interoperability with Java Code

One of the key features of Kotlin is that it is designed to fully interoperate with the Java language syntax. That is, with an existing code base written in Java, it can interact correctly with Kotlin and vice versa.

Easy Learning Curve

The simplicity of the syntax allows for a smooth, intuitive, and short learning curve, perfect for those who want to learn their first programming language. Also, since it is open-source, there is a lot of support from the Kotlin community, which is another great advantage.

Reduced Programming Time

One of Kotlin’s strengths is that it eliminates redundant code, as well as being compact and concise, which greatly optimizes the code writing process and avoids repetition.

Object-Oriented and Functional Programming

Although a goal-oriented paradigm is usually the norm in mobile app development, Kotlin demonstrates that it is also possible to work hand in hand with functional programming. The possibility of working with lambdas in this environment simplifies the most common and tedious tasks in development.


Another great advantage of Kotlin is that the coroutines optimize asynchronous programming, simplifying the tedious work of network calls and database access, and leaving callbacks behind.

Cross-Platform Development

Kotlin can be used for any type of development, from the server-side and client-side web to Android and iOS. Since the language runs on JVM, it allows code sharing between different platforms.


Kotlin gives developers the freedom to work with the style of their choice. Therefore, it is a highly flexible language that has functional and object-oriented constructs. All this translates into a better programming experience.

Kotlin vs. Java

We have already listed the great advantages and features that Kotlin presents, but the great debate mentioned above about the ‘fight’ between Kotlin and Java arises again.

Java has a great track record within the larger communities of the web world. However, the use of Kotlin is increasing day by day, especially for developing mobile applications on Android. What makes them different?

It is a very difficult question to answer since Java is one of the most used programming languages when developing mobile apps, but it is not the only option. Here are some of the differences:

  • In Java, a lot of redundancy results in detailed and longer code. Kotlin is more modern and has been simplified, making it easier for beginners to learn.
  • Kotlin has addressed a number of Java problems, such as no raw types, null references being controlled by the type system, or that it has no marked exceptions. This makes it a very useful language for developers.
  • In addition, Java has other problems regarding endless blocks, lack of extensibility, or lack of support for functional programming.
  • Java syntax is very verbose, especially compared to a modern language like Kotlin.
  • Compared to Java, Kotlin is more secure. Kotlin is Null Safe, that is, by default objects are not null and if we try to assign a null to a variable directly it will not compile. However, in Java, they are very prone to errors.
  • Developing with Kotlin can achieve a 40% reduction in the number of lines of code compared to Java.

Now that you know a little more about these powerful programming languages, you can choose the one that best suits your requirements and needs when developing a project.

Kotlin Testing

To exemplify all the contents we have analyzed above, we will soon share with you a testing practice and a guide for Android using the Page Object Pattern. Stay tuned!

Elena Canorea
Elena Canorea
Communications Lead