Software Development

SOLID

Definition

SOLID is a mnemonic acronym for five design principles intended to make software designs more understandable, flexible, and maintainable. These principles are: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion.

Why It Matters

Adhering to SOLID principles helps developers create systems that are easier to maintain and extend as they grow. They are a guide for creating high-quality, object-oriented designs and avoiding common pitfalls that lead to rigid and fragile code.

Contextual Example

The Single Responsibility Principle states that a class should have only one reason to change. For example, a class that calculates payroll should not also be responsible for saving data to a database. Those should be separate classes.

Common Misunderstandings

  • SOLID principles are guidelines, not absolute laws.
  • They are most applicable in the context of object-oriented programming.

Related Terms

Last Updated: December 17, 2025