When registering dependencies in the ConfigureServices method, you must have seen a pattern like the following code snippet.

Sometimes developing usable components of an application that communicate with legacy components or interfaces of other working systems require components which aren't compatible with each other to be integrated. In a real-world scenario take the example of a system which exposes a micro-USB port for communication, and we have another plugin component which needs to communicate with this system but has a USB port for its access.

The third principle of the SOLID principles, which are five principles describing few fundamental rules for developing arguably ideal software components which are scalable, extensible, robust and flexible, is the Liskov Substitution Principle. This principle can be termed as one of the basic foundations of the Object Oriented Design languages which talks mainly about substitutions and inheritance.

Nulls are one of the most common occurences when developing application logic, or when dealing with entities which can have a possibility of having no referenced value. A Null Object implies to no referenced value or a neutral behaviour. While this is no uncommon, but direct references to null objects can result in "code leakage" or "broken ends", where our application program might have a chance to break. A NullObject Pattern is one of the many design patterns which specifically explains about

With the Repository pattern, we create an abstraction layer between the data access and the business logic layer of an application. By using it, we are promoting a more loosely coupled approach to access our data from the database. Also, the code is cleaner and easier to maintain and reuse. Data access logic is in a separate class, or sets of classes called a repository, with the responsibility of persisting the application’s business model.

Suppose you are building an ASP.NET Core application that stores data in some data store. You want to support multiple data stores and they should be configurable.