Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 3-minute battle to put them to the test.
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11 challenges matching your filters
Clear topic filter- Multiple ChoiceIntermediate
Exactly-once reality
system-designmessagingkafka - Multiple ChoiceIntermediate
Hot partition in Kafka
system-designmessagingkafkasharding - Multiple ChoiceHard
Kafka consumer group rebalance
system-designmessagingkafka - Multiple ChoiceIntermediate
RabbitMQ vs Kafka model
system-designmessagingkafkarabbitmq - Multiple ChoiceBeginner
Kafka partition ordering guarantee
kafkapartitioningordering - Multiple ChoiceIntermediate
Exactly-once via idempotent producer
kafkaexactly-oncetransactions - Code AnalysisHard
Offset commit before processing
system-designmessagingkafka - Code AnalysisHard
Commit before process loses messages
kafkaoffset-commitmessage-loss - Code AnalysisBeginner
Rebalance storm from long processing
kafkarebalanceconsumer-groups - Code AnalysisIntermediate
Kafka transaction + sink exactly-once
kafkaexactly-oncetransactions - Code AnalysisBeginner
Kafka per-key ordering pitfall
kafkaorderingpartitioning
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Every challenge here is drawn from the live Code Royale pool. Review a question, then head to the arena to answer under pressure against a real opponent — 3-minute matches, Elo ranking, and badge tiers on the line.