Clean Architecture

About me

• Lucas
• From Brazil
• 31 years old
• Software Engineer
• Uncle Bob Fan

A very sad story

• Most of the business rules inside the database
• Total of zero unit tests (or integration tests)
• Every "layer" deeply coupled
• Front end attached to angular js

Resulting

Two kinds of value

Behavioural x Structure

"The goal of software architecture is to minimize the human resources required to build and maintain the required system"

SOLID

• SRP
• OCP
• LSP
• ISP
• DIP

SRP

Single Responsibility Principle 

"A class should have only one reason to change."

DIP

Dependency Inversion Principle

VS

Clean Architecture

Entities

• The most important part of the software
• Business rules that  would exist even without the application
• The things that remains true no matter what is happening
• The highest level rules

Use Cases

• Orchestrate the flow of data
• An action performed by a client
• Rules for the application being executed

Port / Adapters

• Everything note directly related to business rules
• Frameworks and Drivers
  • Data base
  • User interface
  • Http Client
  • Controllers 

Some benefits

• Testability
• Easier to reason about
• Decoupling
• Protecting the most important thing (business rules)

Last thoughts

• Keep options open
• Technology changes real fast
• Make things as simple as possible
• Code for other people

Thanks!