Coding Challenges
Build real tools like wc or a Redis server in any language
Coding Challenges is a collection of projects where you build real tools and applications. Examples include your own wc tool, a Redis server, Bitcask, Tetris and Sudoku. Each challenge walks you through the process of creating the application.
Free · No login · Terminal · Intermediate
About Coding Challenges
You can use any programming language. The projects give you deliberate practice on real software instead of small puzzles. They suit developers who already know a language and want to build something bigger.
The site lists more than 100 challenges, and you can read them without an account. John Crickett writes them and shares a new one each week, and you can subscribe on Substack. The site also sells courses and team training.
On Breakpoint since 23 Oct 2026.