91. What is a design pattern?
A reusable solution to a common software design problem.
92. What is Singleton pattern?
Ensures only one instance of a class exists and provides a global point of access.
93. What is Factory pattern?
Encapsulates object creation logic, returning objects based on input parameters.
94. What is Repository pattern?
Abstracts data access logic from business logic, often used with EF Core.
95. What is Dependency Injection pattern?
Injects dependencies into classes rather than creating them internally, improving testability.