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✅ Master Level
SOLID Principles
Complete Beginner → Advanced Syllabus (Pin-to-Pin)
🟢 LEVEL 1
SOLID Fundamentals
Understanding the foundation and goals of SOLID principles.
1. Introduction to SOLID
- Purpose of SOLID principles
- Maintainability goals
- Scalability goals
- Flexibility in software design
- Coupling vs Cohesion
2. Object-Oriented Design Basics
- Classes & objects
- Abstraction
- Encapsulation
- Inheritance
- Polymorphism
🟢 LEVEL 2
S: Single Responsibility Principle (SRP)
A class should have only one reason to change.
3. Responsibility Concepts
- Definition of responsibility
- One reason to change rule
- Separation of concerns
- Business logic vs infrastructure logic
4. Practical Applications
- Function responsibility
- Class responsibility
- Module responsibility
- Component responsibility
🟡 LEVEL 3
O: Open/Closed Principle (OCP)
Open for extension, closed for modification.
5. Extension vs Modification
- Open for extension
- Closed for modification
- Abstraction usage
- Strategy pattern basics
- Plugin-style design
6. Avoiding Conditional Explosion
- Polymorphism over conditionals
- Configuration-driven behavior
🟡 LEVEL 4
L: Liskov Substitution Principle (LSP)
Subtypes must be substitutable for their base types.
7. Substitution Rules
- Behavioral compatibility
- Contract preservation
- Method overriding rules
8. Design Considerations
- Avoid strengthening preconditions
- Avoid weakening postconditions
- Proper inheritance usage
🟠 LEVEL 5
I: Interface Segregation Principle (ISP)
Many client-specific interfaces better than one general-purpose.
9. Interface Design
- Small focused interfaces
- Avoid fat interfaces
- Role-based interfaces
10. Practical Design
- Feature-specific interfaces
- Component props segregation
- Service contract separation
🟠 LEVEL 6
D: Dependency Inversion Principle (DIP)
Depend on abstractions, not on concretions.
11. Dependency Direction
- High-level vs low-level modules
- Depend on abstractions
- Dependency injection basics
12. Implementation Patterns
- Constructor injection
- Factory pattern
- Inversion of control (IoC)
🔵 LEVEL 7
SOLID in Application Design
Applying SOLID across application architecture.
13. SOLID with Design Patterns
- Strategy pattern
- Factory pattern
- Observer pattern
- Adapter pattern
14. Modular Architecture
- Layer separation
- Dependency boundaries
- Testability improvement
🔵 LEVEL 8
SOLID in Frontend Development
SOLID principles applied to React and modern frontends.
15. Component Design
- Single responsibility components
- Presentational vs container components
16. State Management
- Separation of UI and state logic
- Reusable hooks/services
17. API Layer Design
- Service abstraction
- Data transformation layer
🔴 LEVEL 9
Architecture Level SOLID
SOLID at enterprise and large-scale systems.
18. Clean Architecture Alignment
- Domain layer isolation
- Infrastructure independence
- Dependency flow direction
19. Large Scale Systems
- Feature modularization
- Replaceable modules
- Maintainable codebases
⭐ Senior Frontend Focus (Must Master)
Critical SOLID concepts for senior-level frontend engineers:
- Component responsibility boundaries
- Hook abstraction design
- API service abstraction
- Avoiding prop drilling via abstractions
- Dependency injection patterns in frontend
- Reusable UI architecture