In this chapter, we will take a concise, quick, and solid look into the most common and fundamental software industry patterns and practices applied to enterprise grade as well as medium-sized applications.

In this chapter we will learn about the fundamental and modern design & development principles that are essential to the quality and maintainable code for a stable and flexible application design. We will go through some of the frequently used design patterns from the GoF (Gang of Four) and look at their implementation using the .NET Core code.

The topics that we will primarily cover in this chapter include:

• SOLID design principles
• Dependency injection
• GoF design patterns

The code that we will use here will be simple, straightforward and will be used primarily to show the main idea of the pattern.