TenkaCloud is an Apache-2.0 platform for hands-on cloud competitions. It provisions isolated environments for each team, supports self-paced Challenges and continuously scored Battles, and brings access, scoring, fault injection, leaderboards, and cleanup into one operator workflow. Start with a no-signup browser quest, run locally with Docker, or host an event on your own AWS account. The open problem catalog and authoring skill let teams create and reuse their own drills.