Related Skills

Facing a design trade-off (DRY vs KISS)? → Use principles first to decide, then refactor
Code is in the wrong architectural layer? → Use clean-architecture to identify target, then refactor to move it
Need to choose a pattern (Strategy, Factory)? → Use design-patterns first, then refactor toward it
No tests before refactoring? → Use testing to add them first

Applicability Rubric

Condition	Pass	Fail
Existing code modification	Need to change existing code	Writing new code only
Code comprehension issues	Code hard to understand/extend	Code is clear
Feature preparation	Preparing for new functionality	Direct implementation possible
Incremental improvement	Improving quality step by step	No improvement needed

Apply when: Any condition passes