1. SOLID Principles (1 Week)
⏳ Goal: Understand SOLID and implement Java examples.
Day 1: Single Responsibility Principle (SRP) + Code Example
Day 2: Open/Closed Principle (OCP) + Code Example
Day 3: Liskov Substitution Principle (LSP) + Code Example
Day 4: Interface Segregation Principle (ISP) + Code Example
Day 5: Dependency Inversion Principle (DIP) + Code Example
Day 6: Revise SOLID concepts & implement a project
Day 7: Review and improve your Java project based on SOLID
2. Design Patterns (2 Weeks)
⏳ Goal: Learn and implement all 23 design patterns in Java with examples.
📌 Week 1 (Creational + Structural Patterns)
Day 1: Factory Pattern, Abstract Factory Pattern
Day 2: Builder Pattern, Prototype Pattern
Day 3: Singleton Pattern, Adapter Pattern
Day 4: Bridge Pattern, Composite Pattern
Day 5: Decorator Pattern, Facade Pattern
Day 6: Flyweight Pattern, Proxy Pattern
Day 7: Revise and implement a small project using Creational + Structural Patterns
📌 Week 2 (Behavioral Patterns)
Day 8: Strategy Pattern, Observer Pattern
Day 9: Chain of Responsibility Pattern, Command Pattern
Day 10: Interpreter Pattern, Iterator Pattern
Day 11: Mediator Pattern, Memento Pattern
Day 12: Null Object Pattern, State Pattern
Day 13: Template Pattern, Review all behavioral patterns
Day 14: Implement a real-world scenario using behavioral patterns
3. System Design (4 Weeks)
⏳ Goal: Design complex systems with scalable architectures.
📌 Week 1
Day 1-2: Design Splitwise (Expense sharing system)
Day 3-4: Design BookMyShow (Movie ticket booking)
Day 5-6: Design ATM System
Day 7: Revise and optimize design decisions
📌 Week 2
Day 8-9: Design Snake & Ladder Game
Day 10-11: Design Tic Tac Toe (with AI bot)
Day 12-13: Design Elevator System
Day 14: Revise and implement a mini version of one design
📌 Week 3
Day 15-16: Design Parking Lot System (Using Factory & Strategy Patterns)
Day 17-18: Design Car Rental System
Day 19-20: Design Inventory Management System
Day 21: Revise and improve one of the designs
📌 Week 4
Day 22-24: Design Cricbuzz-like System (Live scores & analytics)
Day 25-26: Pick 2 previous designs and optimize them
Day 27-28: Mock System Design Interview + Notes Compilation