SOLID Principles in Software Design

What are SOLID Principles?

SOLID is a mnemonic acronym that represents five fundamental principles of object-oriented programming and design:

• S: Single Responsibility Principle (SRP)
• O: Open-Closed Principle (OCP)
• L: Liskov Substitution Principle (LSP)
• I: Interface Segregation Principle (ISP)
• D: Dependency Inversion Principle (DIP)

Why are SOLID Principles Important?

Understanding and applying SOLID principles helps you:

• Write more maintainable code
• Create more flexible software
• Build scalable applications
• Reduce technical debt
• Make testing easier

Common Interview Questions

1. Basic Understanding

   • "Can you explain what SOLID principles are?"
   • "Why are SOLID principles important in software development?"

2. Implementation

   • "How have you applied SOLID principles in your previous projects?"
   • "Can you identify SOLID violations in this code snippet?"

3. Trade-offs

   • "When might you choose not to follow a SOLID principle?"
   • "How do you balance SOLID principles with practical considerations?"

Preparation Tips

• Study each principle individually
• Practice identifying violations
• Work on refactoring exercises
• Prepare real-world examples
• Understand the relationships between principles