Backend Fundamentals in C#
Understand what a backend does, the client-server model, request-response lifecycle, and how C# and ASP.NET Core fit into modern backend development.
Backend Basics
This lesson establishes what a backend is and what responsibilities it has in a software system.
1. What Is a Backend
Backend as a system, not just code.
2. Backend Responsibilities
What problems backend systems solve.
Frontend and Backend Boundary
Clear boundaries between frontend and backend are critical for secure and maintainable systems.
1. Role of Frontend
What frontend is responsible for.
2. Role of Backend
What backend is responsible for.
Client–Server Model
Most backend systems follow the client–server communication model.
1. Client
Who initiates communication.
2. Server
Who responds to requests.
Request–Response Flow
Understanding this flow is essential before writing APIs.
1. Request Phase
What happens when a request arrives.
2. Response Phase
How a backend sends results.
State Management
State handling has major impact on scalability and reliability.
1. Stateful Systems
Systems that remember information.
2. Stateless Systems
Systems that do not store request context.
C# and .NET in Backend Context
C# with .NET provides a modern, high-performance runtime for building backend services — from minimal APIs to full enterprise applications.
1. The .NET Runtime
What .NET provides for backend development.
2. ASP.NET Core
The web framework powering C# backends.