Learn C# Roadmap

A structured path from zero to job-ready C# developer, covering fundamentals through ASP.NET Core, testing, and deployment.

coding, study

by Morris

Environment Setup

Install and configure all tools before writing a single line of code.

• Install .NET SDK (latest LTS)
• Install Visual Studio 2022 Community or VS Code
• Create and run your first console app
• Configure Git and .gitignore for .NET projects
• Explore the dotnet CLI commands you will use daily
• Bookmark key references: Microsoft Learn and the C# language spec

C# Basics - Types and Variables

Build a solid mental model of the type system before touching classes or OOP.

• Understand value types vs reference types
• Learn the built-in numeric types and when to use each
• Master string interpolation and verbatim strings
• Practice nullable types and the null-coalescing operators
• Understand implicit typing with `var` and when NOT to use it
• Work through Microsoft Learn: C# Foundations path
• Milestone project: unit converter console app

C# Basics - Control Flow and Collections

Loops, conditionals, pattern matching, and the most important built-in collections.

• Master all loop types: for, foreach, while, do-while
• Learn switch expressions (C# 8+) and pattern matching
• Practice List<T>, Dictionary<TKey, TValue>, and HashSet<T>
• Understand arrays vs List<T> and when arrays are appropriate
• Learn collection initializers and object initializers
• Milestone project: word frequency counter

Object-Oriented Programming

Classes, interfaces, inheritance, and the OOP features that C# emphasizes in production code.

• Understand classes, constructors, properties, and access modifiers
• Learn records for immutable data models (C# 9+)
• Practice interfaces and coding to an abstraction
• Understand when to use inheritance vs composition
• Learn static classes and extension methods
• Understand structs and when they outperform classes
• Milestone project: bank account OOP model

Intermediate C# - LINQ

LINQ is used everywhere in C# code. Master it early - it transforms how you think about collections.

• Learn LINQ method syntax for the 10 most-used operators
• Understand deferred execution vs immediate execution
• Practice LINQ on real data: JSON deserialization + querying
• Learn `FirstOrDefault` vs `SingleOrDefault` and when each is correct
• Understand `IEnumerable<T>` vs `IQueryable<T>`
• Milestone project: CSV data analyzer

Intermediate C# - Async/Await and Error Handling

Asynchronous programming is non-negotiable for modern .NET. Learn it correctly now.

• Understand the Task-based async model: Task, Task<T>, and ValueTask
• Learn the async all the way down rule
• Practice `HttpClient` with async: call a public API
• Understand CancellationToken and why it matters
• Master structured exception handling in C#
• Learn ConfigureAwait(false) and when it is needed
• Milestone project: async weather CLI tool

Generics, Delegates, and Functional Patterns

The features that make C# expressive and reusable at scale.

• Write your own generic type and generic method
• Understand generic constraints: where T : class, new(), IComparable<T>
• Master Func<T>, Action<T>, and Predicate<T> delegates
• Learn events and the standard EventHandler<T> pattern
• Practice iterator methods with `yield return`

The .NET Ecosystem: NuGet and Key Libraries

Know the most important NuGet packages before starting ASP.NET Core work.

• Learn NuGet basics: add, update, and audit packages
• Learn Serilog for structured logging
• Learn AutoMapper or Mapster for DTO mapping
• Learn FluentValidation for input validation
• Learn Polly for resilience: retries, circuit breakers, timeouts
• Learn MediatR for the mediator / CQRS pattern
• Explore BenchmarkDotNet for micro-benchmarking

ASP.NET Core - Building a REST API

The primary .NET web framework. Focus on minimal APIs first, then controller-based APIs.

• Scaffold a minimal API project and understand Program.cs
• Learn the dependency injection (DI) container and service lifetimes
• Implement CRUD endpoints with validation and proper HTTP status codes
• Configure middleware pipeline in the correct order
• Add JWT authentication with Microsoft.AspNetCore.Authentication.JwtBearer
• Understand the Options pattern for configuration

Entity Framework Core - Data Access

The standard ORM for .NET. Used in the majority of .NET job roles.

• Set up EF Core with PostgreSQL or SQL Server
• Define a DbContext and entity models
• Learn and use EF Core migrations
• Understand eager loading vs lazy loading vs explicit loading
• Learn the Repository pattern and when NOT to use it
• Practice writing efficient EF queries: projections and no-tracking

Testing with xUnit and Moq

Untested C# is a liability. Learn the standard test stack used in most .NET projects.

• Set up an xUnit test project
• Write unit tests for pure business logic: Arrange-Act-Assert
• Use Moq to mock dependencies
• Write integration tests with WebApplicationFactory
• Use Testcontainers for real database integration tests
• Learn FluentAssertions for readable test assertions

Capstone Project and Interview Prep

Build a complete project, then prepare for technical interviews.

• Capstone project: build a REST API with full stack
• Add a README and OpenAPI documentation to the capstone
• Review C# interview topics: value vs reference, boxing, string immutability
• Practice LeetCode / NeetCode problems in C#
• Study system design fundamentals for senior-track roles
• Deploy the capstone project to a free cloud host