Tell me about the principles of SOLID.

The SOLID principles are a set of five core principles of object-oriented design aimed at creating flexible, extendable, and maintainable systems:

• S (Single Responsibility Principle) — the principle of single responsibility. Each class should have one and only one reason to change.
• O (Open/Closed Principle) — the principle of openness/closedness. Software entities should be open for extension but closed for modification.
• L (Liskov Substitution Principle) — Barbara Liskov's substitution principle. Subclass objects should be interchangeable with superclass objects without breaking the correctness of the program.
• I (Interface Segregation Principle) — the principle of interface segregation. Clients should not depend on interfaces they do not use.
• D (Dependency Inversion Principle) — the principle of dependency inversion. High-level modules should not depend on low-level modules; both should depend on abstractions.

In Go, despite the absence of traditional OOP, these principles are applicable through interfaces and composition. For example, interfaces help implement the interface segregation and dependency inversion principles.