Five principles, each with a one-line rule, a before → after sketch, and the smell it kills.
Mark what you know, take the quiz, then copy a study prompt tuned to your gaps.
Preset
The five principles
click a code smell's toggle to flip Before / After · tap the pill to mark your grasp
Guided quiz
read the symptom, name the principle it violates
Study prompt— built from your marks & quiz results