Interface Segregation Principle

ISP

• Keep interfaces small so that users don’t depend on things they don’t need.
• ISP is intended to keep a system decoupled and thus easier to refactor, change, and redeploy
• Many client-specific interfaces are better than one general purpose interface.
• The principle of separating interfaces from the client's perspectives

When interface which we don't use is changed, Client use the interface need to recompile, rebuild and deployed again. If we stick to ISP, Program can get decoupled.