Learn C# Like
an Adventure

Eleven worlds of real coding challenges, each one building on the last. Write actual C# that compiles and runs. No passive video courses — learn by doing.

Begin Your JourneyFree forever. No tricks.

What you'll actually learn

Not a checklist. A real progression from first syntax to production patterns.

◈

C# fundamentals, built up slowly

Variables, types, control flow — taught through real problems, not slides. By the end of World 1 you're already writing something that works.

⬡

Object-oriented thinking

Classes, inheritance, polymorphism. You'll model real things, not toy examples, until the concepts click naturally.

≋

LINQ, async/await, and modern C#

The parts that separate a working developer from a fluent one. Covered in dedicated worlds with challenges that force real understanding.

▦

Design patterns and architecture

The final worlds cover the patterns that show up in every serious codebase — dependency injection, clean architecture, SOLID principles.

How it works

1

Choose a world

Start at C# Foundations or jump to where you are. Each world is a self-contained arc of challenges.

2

Solve challenges

Read the problem, write real C# in the editor, submit. Tests run instantly. You see what passed and what didn't.

3

Level up

Earn XP, unlock the next world, and watch your skills compound across 600+ challenges.

Eleven worlds, one journey

Each world focuses on a distinct area of C#. Complete all eleven and you'll have covered the full language.

C# FundamentalsWorld 1

Variables, types, control flow

Object-Oriented ProgrammingWorld 2

Classes, inheritance, interfaces

Collections & GenericsWorld 3

Lists, dicts, sets, IEnumerable

LINQWorld 4

Queries, lambdas, sequences

Async / AwaitWorld 5

Tasks, async/await, concurrency

ASP.NET CoreWorld 6

APIs, middleware, routing

Entity Framework CoreWorld 7

ORM, migrations, queries

SQL ServerWorld 8

Schemas, indexes, transactions

Architecture & Design PatternsWorld 9

DI, SOLID, design patterns

TestingWorld 10

Unit tests, mocks, TDD

Interview Boss RushWorld 11

Real interview challenges

What a challenge looks like

A real problem statement, a real editor, real test results.

World 3 — LINQ Labyrinth

Filter & Sort a Collection

Given a list of Product objects, use LINQ to return only those with a price under $50, ordered by name ascending.

Test cases

  • 5 products in, 3 under $50 → returns 3
  • Results are alphabetical by name
  • Empty list → returns empty list
✓Returns correct count
✓Sorted alphabetically
✗Handles empty input
Solution.cs
public IEnumerable<Product>
GetAffordable(List<Product> products)
{
    return products
        .Where(p => p.Price < 50)
        .OrderBy(p => p.Name);
}

Ready to start?

Create a free account and begin World 1 in the next two minutes. No setup, no credit card, no catch.

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