CodeCrafters

What is CodeCrafters?

CodeCrafters is a programming practice platform for experienced software engineers. You rebuild real tools such as Redis, Git, SQLite, Kafka, an HTTP server and a shell from scratch, stage by stage, in your preferred language and editor, and every git push runs automated tests that give feedback within seconds.

Tutorials rarely teach how the tools you use every day actually work. CodeCrafters breaks systems like a Redis server or a BitTorrent client into small stages with tests, so you learn protocols, parsers and storage internals by writing them yourself. Because you code locally in your own IDE and submit with git push, the practice feels like real engineering work rather than a browser exercise.

Main Features

• Challenges include Redis, Shell, Interpreter, Git, SQLite, Kafka, HTTP Server, BitTorrent, Grep and DNS Server.
• A newer challenge walks you through building a Claude Code style agent using LLM APIs and agent loops.
• Each challenge is split into stages, for example 97 stages for Redis and 14 for the HTTP server.
• You write code in your own IDE and run tests with a git push.
• Test results and hints come back within seconds of each push.
• Multiple programming languages are supported per challenge, so you can learn a new language along the way.
• Teams plans add a team leaderboard, usage analytics and a Slack app.

How to Get Started with CodeCrafters

1. Sign up on CodeCrafters with GitHub, no credit card needed for the free plan.
2. Pick a challenge such as Redis or Git and choose your programming language.
3. Clone the starter repository, implement the first stage and git push to run the tests.
4. Work through later stages, then upgrade to a membership for full content access.

CodeCrafters Pricing

The free plan offers limited content and community features with no credit card. Membership lifts content limits and adds turbo tests and code examples, with 3-month, 1-year and lifetime billing; prices are shown at checkout.

Who Should Use It?

• Mid-level and senior engineers who want to understand systems internals
• Developers learning a new language such as Rust or Go through real projects
• Engineers preparing for systems design and backend interviews
• Engineering teams running shared upskilling with a leaderboard

CodeCrafters Alternatives

• DataCamp: better for data science and analytics courses
• Llama Tutor: open-source AI tutor for general topics, not coding projects
• Quizgecko: turns notes into quizzes rather than hands-on builds

Frequently Asked Questions

Is CodeCrafters free?

Partly. The free tier gives limited access to challenge content plus community features. A paid membership opens all stages, instant turbo tests and code examples, and many employers let engineers expense it from a learning budget.

What can you build on CodeCrafters?

You can rebuild Redis, Git, SQLite, Kafka, a shell, an interpreter, an HTTP server, a DNS server, grep and a BitTorrent client, plus an AI coding agent, each broken into tested stages.

How does CodeCrafters test your code?

You write code in your own editor, commit it and git push to the remote. Automated tests for the current stage run on their servers and report results and hints within seconds.