What are the advantages of layered architecture?

#Advantages of layered architecture

1. Separation of responsibility. Each layer plays a strictly defined role - the interface does not interfere with the business logic, and the business logic does not depend on the database. This makes the system clearer and more structured.
2. Simplified maintenance. Because of the clear boundaries between layers, changes in one place have minimal effect on the rest. For example, the database can be replaced without touching the application's logic.
3. Code reuse. The same layer (for example, the domain logic) can be used by different interfaces - a web application, a mobile client, an API.
4. Improved testability. Each layer can be checked separately. For example, the business logic can be tested without launching the interface or connecting a database.
5. Flexibility and extensibility. It is easier to add new features or adapt the system to other technologies, because the dependencies between layers are minimal and controlled.
6. Increased reliability. A clear structure reduces the risk of errors caused by chaotic connections between components - the system becomes more resilient to change.