| Book Exercise Lanes | exercise | 1 | Open |
| Code Katas | practice | 1 | Open |
| Cohesion, Coupling, and SOLID Lab | practice | 1 | Open |
| Cohesion: A Class Does One Thing Well | concept | 3 | Open |
| Comments: When Needed, When They Lie | concept | 5 | Open |
| Compatibility and Evidence for Design Changes | concept | 1 | Open |
| Composition, Functional Cores, and Extension Axes | concept | 1 | Open |
| Coupling: Minimize What a Module Needs to Know | concept | 3 | Open |
| Dependency Inversion: Depend on Abstractions, Not Concretions | concept | 3 | Open |
| Encapsulation and Information Hiding as Design Goals | concept | 3 | Open |
| Evaluation Order and Effects | concept | 1 | Open |
| Explicit Outcomes and Observable Behavior | concept | 1 | Open |
| Functions Should Do One Thing, at One Level of Abstraction | concept | 3 | Open |
| Interface Segregation: Small, Role-Based Interfaces | concept | 3 | Open |
| Learning Resources | resource | 5 | Open |
| Liskov Substitution: Subtype Contracts | concept | 3 | Open |
| Long Method, Large Class, Feature Envy, Data Clumps | concept | 2 | Open |
| Names Reveal Intent | concept | 4 | Open |
| Naming and Function Refactor Workshop | practice | 1 | Open |
| Object-Oriented Design and Smells: Reading Guide | other | 2 | Open |
| Open-Closed Principle: Extend Without Modifying | concept | 3 | Open |
| Ownership, Aliasing, and Immutable Snapshots | concept | 1 | Open |
| Primitive Obsession, Switch Statements, Speculative Generality | concept | 2 | Open |
| Products, Sums and Valid States | concept | 1 | Open |
| Reference and Selective Reading | reference | 7 | Open |
| Shotgun Surgery, Divergent Change, and Parallel Inheritance Hierarchies | concept | 1 | Open |
| Single Responsibility Principle: Reasons to Change | concept | 3 | Open |
| Smell Identification Clinic | practice | 1 | Open |
| State-Machine Contracts and Failure Atomicity | concept | 1 | Open |
| When NOT to Apply a Principle: YAGNI vs Premature Abstraction | concept | 3 | Open |