What is SOLID? Decode the principles.

SOLID is a set of five principles of object-oriented programming aimed at creating flexible and maintainable code:

• S (Single Responsibility Principle) — The Single Responsibility Principle: a class should have only one reason to change, meaning it should perform only one task.
• O (Open/Closed Principle) — The Open/Closed Principle: software entities should be open for extension but closed for modification.
• L (Liskov Substitution Principle) — Barbara Liskov's Substitution Principle: objects of a subclass should be interchangeable with objects of the superclass without affecting the correctness of the program.
• I (Interface Segregation Principle) — The Interface Segregation Principle: it's better to have several specific interfaces than a single general-purpose interface.
• D (Dependency Inversion Principle) — The Dependency Inversion Principle: high-level modules should not depend on low-level modules; both should depend on abstractions.

Example in Go illustrating SRP and DIP:

// Single Responsibility Principle
type Logger interface {
    Log(message string)
}

// Dependency Inversion Principle
func ProcessData(data string, logger Logger) {
    // data processing
    logger.Log("Data processed")
}