Build Week
Ship one small project in 7 days
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Coding · Facts & stats · iChallenge network
The arena for data — ship it, score it, rank it. Play today's round, build a streak, climb the leaderboard.
In most mainstream languages like C, Java and Python, arrays start at which index?
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One ranked attempt per day. Practice as much as you like.
Join one, log your days or post your proof. Finishing earns XP and the Finisher badge.
Ship one small project in 7 days
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Climb the weekly problem ladder
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Contribute one fix to open source
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Live counts from DataChallenges.com. All arena stats →
Earned on any arena, shown on your profile everywhere.
Add your email to keep your level, streak and badges if you switch devices, and carry them to every iChallenge arena. One email when you save; no spam.
Fund a prize on DataChallenges.com and your brand sits on the challenge card, the leaderboard and every finisher's share. Prizes only appear once they're funded, so players can trust what they see.
Any language. Challenges score consistency and completion, not syntax.
Yes — quiz rounds start easy and scale with your streak.
Everyone on this arena gets the same five questions each day, from easy to hard. You get one ranked attempt; practice rounds are unlimited.
100 points per correct answer, up to 50 more for answering quickly, a combo multiplier for answers in a row, and 150 bonus points for a perfect round.
Yes. Playing, streaks, badges and leaderboards are free. Some challenges carry a sponsor-funded prize; the challenge card shows it when one is funded.