What are design principles and design patterns?

Problem Explain the difference between design principles and design patterns, with examples.

Be ready to discuss

• Design principles: general OO guidelines — SOLID, DRY, KISS, YAGNI.
• Design patterns: named reusable solutions — Factory, Strategy, Observer, etc.
• Concrete examples of each and where you have applied them.
• How principles inform when (and when not) to reach for a pattern.