What is DTO? Why use?

Hello everyone, I'm Jean and I'm here to bring you an article about DTO. This is just theory, and there will be no practical code. I hope you enjoy it!

Introduction

DTO, or "Data Transfer Object," as the name suggests, is an object used to send and receive data. It is typically used in the backend of more structured applications.

But why use DTO?

DTO is a way to simplify and separate, providing several benefits such as:

1. 
   Encapsulation: Based on clean architecture and SOLID principles, it is a way to group/limit data for better organization and separation from business logic and other layers.


2. 
   Coupling reduction: By reducing coupling, there is better control over code maintenance and scalability, in addition to enabling testing and other types of manipulation.


3. 
   Security and control: By better separating and controlling data, it is possible to implement validators, security and validation systems, and reduce leaks of sensitive information.


4. 
   Performance: Although in some cases there is no direct improvement, the use of DTOs allows for better control and reduction of unnecessary data, resulting in smaller network packets and potentially improving performance.


5. 
   Ease of testing: By isolating parts of the system, it is possible to simulate scenarios (mock), carry out isolated tests, and have better visibility of the data flow.

How to use it?

There are several ways of implementation, and here are some examples in different languages:

1. 
   JavaScript:
   


2. 
   Rust (Reddit): Are DTOs and Entities the Right Way?
   

When to use DTO?

I listed some contexts to explain why to use DTO:

• 
  Web service applications: Better control of the data flow to receive and return information, establishing a clear contract between client and server.


• 
  Distributed systems: In microservices and API architectures, it is beneficial to control and gain better insight into the system, as well as reducing latency due to decreased network traffic.

Conclusion

DTO is an excellent way to organize, separate, optimize, test, and perform several other tasks within an application. The concept is similar to GRPC, which also uses a well-defined structure. Anyway, I hope you liked it.