Clean Architecture: A Craftsman's Guide to Software Structure and Design

by Robert C. Martin

SRP: The Single Responsibility Principle An active corollary to Conway’s law: The best structure for a software system is heavily influenced by the social structure of the organization that uses it so that each software module has one, and only one, reason to change. • OCP: The Open-Closed Principle Bertrand Meyer made this principle famous in the 1980s. The gist is that for software systems to be easy to change, they must be designed to allow the behavior of those systems to be changed by adding new code, rather than changing existing code. • LSP: The Liskov Substitution Principle Barbara Liskov’s famous definition of subtypes, from 1988. In short, this principle says that to build software systems from interchangeable parts, those parts must adhere to a contract that allows those parts to be substituted one for another. • ISP: The Interface Segregation Principle This principle advises software designers to avoid depending on things that they don’t use. • DIP: The Dependency Inversion Principle