To achieve a loosely coupled and highly cohesive codebase, focus on these top three strategies: 1. **Embrace Modular Design:** Break down your application into discrete modules or services, each responsible for a specific piece of functionality. Use interfaces or abstract classes to define how modules communicate, minimizing direct dependencies. This modular approach enhances cohesion within components and reduces coupling between them, making your code more flexible and easier to manage. 2. **Adopt Dependency Injection (DI):** DI is a design pattern that allows a component's dependencies to be injected into it, rather than hard-coded. By using DI, you decouple your classes from their dependencies, making your system more modular and testable. It allows for better separation of concerns and makes your codebase more adaptable to changes. 3. **Leverage Design Principles and Patterns:** Familiarize yourself with and apply solid design principles, such as the Single Responsibility Principle (SRP), Open/Closed Principle (OCP), and Interface Segregation Principle (ISP) from SOLID principles. Utilize design patterns like the Factory, Strategy, and Observer where appropriate. These principles and patterns guide you in creating a system that is easier to maintain, extend, or modify, promoting both high cohesion within modules and loose coupling between them.