Monorepository with C#: Code Organization for Beginners

Monorepository with C#: Code Organization for Beginners

In modern C# (.NET) development, the question inevitably arises sooner or later: how to organize code when you have several projects — a class library, a web API, a console application, tests? Many beginner developers create separate repositories for each part, leading to confusion with versions and dependencies. An alternative is a monorepository (monorepo). In this article, we will break down what a monorepository is, how to set it up in C#, and why it simplifies life for beginners.

What is a Monorepository?

A monorepository is an approach where all the code of several related projects is stored in a single Git repository. For example, you might have a shared library MyApp.Shared, a web application MyApp.Web, and a console tool MyApp.Cli — all in one folder, with one .sln file.

In the context of C# (.NET), a monorepository usually means a single Visual Studio Solution containing multiple projects. This is especially convenient for:

• Sharing code (via Project References, rather than NuGet packages).
• A unified build and CI/CD process.
• Simplifying version management (one branch — all changes at once).

Benefits of a Monorepository for Beginners

If you are just starting to learn C#, a monorepository will help you avoid common mistakes:

• Ease of navigation — all projects in one place, no need to switch between repositories.
• Instant connectivity — a change in the library is immediately visible in dependent projects.
• Unified style — you can configure one .editorconfig or Directory.Build.props for all projects.
• Easy to run tests — a single dotnet test command checks the entire solution.

Creating a Monorepository Structure: Step-by-Step Guide

Step 1. Create the root folder and solution

Open a terminal and run:

mkdir MyMonorepocd MyMonorepodotnet new sln -n MyApp

Now you have a MyApp.sln file — the entry point for Visual Studio or Rider.

Step 2. Add projects

Let's create three projects: a class library, a web API, and a console application. For convenience, place them in a src subfolder:

mkdir srccd srcdotnet new classlib -n MyApp.Shareddotnet new webapi -n MyApp.Webdotnet new console -n MyApp.Clicd ..

Now link them to the solution:

dotnet sln add src/MyApp.Shared/MyApp.Shared.csprojdotnet sln add src/MyApp.Web/MyApp.Web.csprojdotnet sln add src/MyApp.Cli/MyApp.Cli.csproj

Step 3. Configure dependencies between projects

Suppose MyApp.Web and MyApp.Cli use classes from MyApp.Shared. Instead of publishing the library to NuGet, simply add a Project Reference:

dotnet add src/MyApp.Web/MyApp.Web.csproj reference src/MyApp.Shared/MyApp.Shared.csprojdotnet add src/MyApp.Cli/MyApp.Cli.csproj reference src/MyApp.Shared/MyApp.Shared.csproj

Now the MyApp.Web.csproj file will have a section:

<ItemGroup>  <ProjectReference Include="..\\MyApp.Shared\\MyApp.Shared.csproj" /></ItemGroup>

Step 4. Write shared code

In the MyApp.Shared project, let's create a simple class:

// src/MyApp.Shared/GreetingService.csnamespace MyApp.Shared;

public class GreetingService{    public string GetGreeting(string name) => $"Hello, {name}! Welcome to the monorepository.";}

Now use it in the console application:

// src/MyApp.Cli/Program.csusing MyApp.Shared;