Codewars
Small programming problems where, once you solve one, you can read everyone else's solution. Seeing five better answers to something you just solved is the fastest way to improve.
- Computer Science
- Who can enter
- Anyone worldwide. Free account; 20+ languages, and the problems start genuinely easy
- What it costs
- The problems, the solutions and the community are free. An optional paid tier adds extra practice features, and you never need it.
- When it closes
- We could not confirm this year's date against the organiser's own page, so we are not showing a countdown for it. Last published: Open all year: solve a kata any time, free.
Sending this to someone sends the four facts above, not just a name. They will see who can enter and what it costs before they decide.