JavaScript Tutorials

  • Learn by practice: unique and fluent tutorials in koan style.
  • No sandboxes: write code in your own IDE, run it on your own machine.
  • No crowd-sourcing: all exercises are created and solved by expert engineers.
  • Exercise variety: quizzes, tasks, refactorings, etc.

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React is the most popular tool to create single page applications (SPA). SPA are actively supplanting “normal sites”, since they do not require a page reload for every user action and provide the best UX (user experience).

1 tutorial

Programming Fundamentals

Represent human data as code and transform it with basic algorithms. Master variables, datatypes, functions, expressions and statements, mutability, etc. From zero to a real problem-solving code.

2 tutorials


Solve C10k problem and build scalable web servers with NodeJS. Master platform APIs, builtins, module system, networking, and async IO. From basics to your own realtime server.

5 tutorials

Functional Programming

Use functions as the main unit of composition and code reuse. Master purity, immutability, closures, currying, lenses, recursion patterns, etc. From basics to your own library code.

9 tutorials

Asynchronous Programming

Parallelize the IO operations with async code and event-driven architecture. Master callbacks, promises, emitters, streams, async-await, reactivity, etc. From basics to your own library code.

2 tutorials