design-principles

name	design-principles
description	Unified software design principles — SOLID, GRASP, DRY, KISS, YAGNI, BIG-O
version	1.0.0
triggers	["designing architecture","reviewing code","refactoring"]

Design Principles

SOLID

• Single Responsibility: One reason to change per class/module
• Open/Closed: Open for extension, closed for modification
• Liskov Substitution: Subtypes must be substitutable for base types
• Interface Segregation: Many specific interfaces over one general
• Dependency Inversion: Depend on abstractions, not concretions

GRASP

• Information Expert: Assign responsibility to the class with the information
• Creator: Assign creation to the class that has the initialising data
• Controller: Assign system events to a non-UI class
• Low Coupling / High Cohesion: Minimise dependencies, maximise focus

DRY (Don't Repeat Yourself)

Every piece of knowledge has a single, authoritative representation. Three similar lines of code is NOT a DRY violation — premature abstraction is worse.

KISS (Keep It Simple)

The right amount of complexity is the minimum needed for the current task.

YAGNI (You Aren't Gonna Need It)

Don't build for hypothetical future requirements.

BIG-O

Be aware of algorithmic complexity. Flag O(n^2)+ patterns.