Advanced LLD Topics — A Deep Dive Who this is for: Anyone who has finished the SOLID principles and the three design-pattern modules (Creational, Structural, Behavioural) and is ready to learn how to use that knowledge well — in real systems, in real interviews, in real production code. What this module builds on: SOLID Principles (Module 2), Creational Patterns (Module 3), Structural Patterns (Module 4), Behavioural Patterns (Module 5). What this module feeds into: Case Studies (Module 9) and Testing (Module 8). The Dependency Injection section here is the foundation for every fake, mock, and stub you’ll write in Module 8. ...

Design Patterns, Part 1: Foundations and Creational Patterns Table of Contents What a Design Pattern Is Why Design Patterns Are Studied Classification of the GoF Catalogue The Template Used for Each Pattern The Problem Space of Creational Patterns Singleton Factory Method Abstract Factory Builder Prototype Comparative Summary of the Five Patterns Key Takeaways Practice Exercises with Solutions Self-Assessment Questions 1. What a Design Pattern Is 1.1 Definition Design pattern. A named, general, reusable solution to a problem that recurs within a particular context of software design. A pattern is a description of communicating objects and classes that are customised to solve a general design problem in that context. ...

Design Patterns — Part 2: Structural Patterns Who this is for: Anyone who has worked through the Creational patterns and is ready to learn how objects fit together — how to combine classes and objects into larger structures that stay flexible and maintainable. Table of Contents Structural Patterns — What and Why Adapter Bridge Composite Decorator Facade Flyweight Proxy Summary of Structural Patterns Practice Exercises with Solutions Self-Assessment Test 1. Structural Patterns Creational patterns answered: “how do we make objects flexibly?” Structural patterns answer: “how do we combine objects into larger structures flexibly?” ...