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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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20 challenges matching your filters
Clear topic filter- Multiple ChoiceBeginner
At-least-once semantics
system-designmessagingidempotency - Multiple ChoiceIntermediate
Exactly-once reality
system-designmessagingkafka - Multiple ChoiceIntermediate
Backpressure
system-designmessagingbackpressure - Multiple ChoiceBeginner
Dead letter queue
system-designmessagingdlq - Multiple ChoiceBeginner
Poison message and head-of-line blocking
system-designmessagingdlq - 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
SQS visibility timeout
system-designmessagingsqs - Multiple ChoiceHard
Visibility timeout too short
system-designmessagingsqsidempotency - Multiple ChoiceIntermediate
Outbox relay ordering
system-designoutboxmessaging - Multiple ChoiceBeginner
Exactly-Once vs At-Least-Once Semantics
exactly-onceidempotencymessaging - Code AnalysisIntermediate
Consumer without dedup
system-designmessagingidempotency - Code AnalysisIntermediate
Unbounded in-memory queue
system-designmessagingbackpressure - Code AnalysisIntermediate
Exactly-once assumption in consumer
system-designmessagingsqsidempotency - Code AnalysisHard
At-least-once with side effect before ack
system-designmessagingidempotency - Code AnalysisHard
Backpressure via unbounded broker retention
system-designmessagingbackpressure - Code AnalysisIntermediate
Queue with no DLQ and infinite retry
system-designmessagingdlq - Code AnalysisIntermediate
Fire-and-forget event loss
system-designmessagingoutbox - Code AnalysisHard
Offset commit before processing
system-designmessagingkafka
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