The Liskov Substitution Principle (LSP) is the “L” in SOLID, but it might as well stand for “Look, this seems fine… until runtime.” If you’ve ever inherited from a class only to spend the next two weeks duct-taping behavior back together, you’ve danced with the devil that is LSP.

Strength based leadership: Your strengths are not something to “check off.” They’re your leadership engine.

Software entities should be open for extension, but closed for modification