Learn .NET The best app for learning to code.
Desktop app for learning C# and .NET 10. Real IntelliSense, a real debugger, and an AI tutor that actually reads your code.
Lifetime license Windows 10/11. 7-day refund
Pay once. It's yours forever.
One-time license, free 1.x updates, works offline
The real environment
Editor, debugger, and compiler — the tools you'll use at work.
Microsoft's Roslyn — the C# engine behind Visual Studio and VS Code — plus your local .NET SDK. Errors show up as you type; Run compiles code on your machine.
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AI tutor
Bring your own AI — free tier or paid, no extra cost.
DevJourney drives OpenAI's Codex CLI and Anthropic's Claude Code CLI — the same tools professionals use — locally, as a subprocess that sees your code and your lesson. A paid plan is optional: the free tiers work too, with no markup on top.
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590+ lessons. 52 chapters.
Nine parts walk you from Console.WriteLine through OOP, LINQ, async, testing, and EF Core to Web APIs, and end on a task-management app you build. The whole course, over 590 lessons, is available in full in English and Polish.
- 01What Is Programming?
- 02Meet C# and .NET
- 03Your First Program
- 04Values, types, and variables
- 05Operators, strings, and expressions
- 06Control flow
- 07Methods
- 08Collections basics and error handling
- 09Project: Word Frequency CLI
- 10Classes and objects
- 11Inheritance and polymorphism
- 12Interfaces and abstract types
- 13Structs, records, and enums
- 14Project: Mini Library
- 15Generics
- 16Collections deep dive
- 17Delegates, lambdas, and events
- 18LINQ
- 19Project: Sales Report (LINQ)
- 20Asynchronous programming
- 21Project: Mini Pub/Sub
- 22Modern C# Features and Patterns
- 23Projects, Packages, and Tooling
- 24Files, Streams, and Serialization
- 25Application Building Blocks
- 26Unit Testing with xUnit
- 27Project: Markdown → HTML
- 28Project: TDD String Utils
- 29Database fundamentals
- 30EF Core Foundations
- 31Modeling data and migrations
- 32Advanced data access
- 33Saving, transactions, and performance
- 34Project: Forum Threads
- 35Introduction to Web Development
- 36Your first ASP.NET Core API
- 37Your First Web API
- 38Routing and Middleware
- 39Minimal APIs and Controllers
- 40Binding, Validation, and Content
- 41Consuming HTTP APIs
- 42Authentication
- 43Authorization
- 44Cross-Cutting Concerns
- 45Documentation, Versioning, and Real-Time
- 46Integration Testing
- 47Debugging and Performance
- 48Security Essentials
- 49Deployment and Operations
- 50Application Architecture
- 51Project: TaskTracker — production-ready
- 52TaskTracker
Project — TaskTracker
A real web app for task management: ASP.NET Core Razor Pages + EF Core + SQLite, with an xUnit test suite. Multi-file editor, built-in HTTP client to test the endpoints.
PROGRAMMING & AI
Yes, it's still worth learning to code.
The question everyone's asking: if AI writes so much of the code, why learn it yourself? Because AI raised the value of understanding code — it didn't remove it. Five honest reasons:
Further reading: The 70% problem (Osmani) / How I use LLMs (Willison)
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You can't review what you can't read
AI produces a plausible answer in seconds. Deciding whether it's correct, secure, and worth shipping is the job now — and that takes someone who reads code fluently.
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When generated code breaks, understanding gets you out
Re-prompting a bad fix tends to add two new bugs. Reading a stack trace and stepping through a debugger is how you break out of the loop.
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AI extends the programmer — it doesn't replace one
It multiplies the output of someone who knows what they're doing. It can't supply the judgment from nothing; experienced instincts are exactly what pull the best results out of it.
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Fundamentals are the moat now
Once AI commoditizes the obvious code, your edge is what it's bad at: architecture, data modeling, performance, security, tradeoffs. That knowledge is worth more, not less.
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Learn it yourself first, then let AI accelerate you
Let AI do your thinking while you learn and you end up with a black box you can't debug. Build the mental model by writing real code — then hand the boring parts to the machine.