SOLID Principles: Introducing Software Architecture & Design

Writing code that works is not enough—great software must also be clean, maintainable, scalable, and easy to evolve.

This course introduces you to the SOLID Principles, the foundation of modern free software architecture course and object-oriented design used by professional developers worldwide.

In this course, you’ll learn why bad design leads to fragile, tightly coupled systems and how applying SOLID principles helps you build flexible, testable, and future-proof applications. Each principle is explained step by step, starting from the problem, moving to the design flaw, and finally arriving at the correct, SOLID-compliant solution.

The course focuses on real-world scenarios, not just theory. You’ll see how SOLID principles are applied in Object-Oriented languages like Java and how they naturally lead to clean architecture, better abstractions, and improved system design.

SOLID Principles Covered

S — Single Responsibility Principle (SRP)

O — Open/Closed Principle (OCP)

L — Liskov Substitution Principle (LSP)

I — Interface Segregation Principle (ISP)

D — Dependency Inversion Principle (DIP)

Each principle is explained using simple language, step-by-step examples, and before-and-after refactoring, so you clearly see the impact of good vs bad design.

By the end of this course, you won’t just know SOLID principles—you’ll be able to apply them confidently in real-world projects, making your codebase robust, scalable, and future-proof.