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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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19 challenges matching your filters
Clear topic filter- Multiple ChoiceBeginner
Strategy vs if/else
architecturedesign-patternsstrategy - Multiple ChoiceHard
Observer and memory leaks
architecturedesign-patternsobserver - Multiple ChoiceBeginner
Factory Method vs Abstract Factory
architecturedesign-patternsfactory - Multiple ChoiceBeginner
Adapter vs Facade
architecturedesign-patternsadapterfacade - Multiple ChoiceIntermediate
Decorator vs inheritance
architecturedesign-patternsdecorator - Multiple ChoiceBeginner
Command pattern: undo
architecturedesign-patternscommand - Multiple ChoiceIntermediate
Repository vs DAO
architecturedesign-patternsrepository - Multiple ChoiceHard
Unit of Work and aggregate boundaries
architecturedesign-patternsunit-of-workddd - Multiple ChoiceBeginner
Sidecar vs Ambassador
architecturedesign-patternssidecarambassador - Multiple ChoiceBeginner
Facade reduces coupling
architecturedesign-patternsfacade - Multiple ChoiceIntermediate
Decorator ordering matters
architecturedesign-patternsdecorator - Multiple ChoiceIntermediate
Strategy vs State
architecturedesign-patternsstrategystate - Code AnalysisIntermediate
Observer memory leak
architecturedesign-patternsobserver - Code AnalysisIntermediate
Decorator vs subclass explosion
architecturedesign-patternsdecorator - Code AnalysisIntermediate
Repository leaking persistence
architecturedesign-patternsrepository - Code AnalysisHard
Facade hides subsystem steps
architecturedesign-patternsfacade - Code AnalysisBeginner
Command with undo
architecturedesign-patternscommand - Code AnalysisIntermediate
Ambassador vs Sidecar use
architecturedesign-patternssidecarambassador - Code AnalysisIntermediate
Adapter vs Facade distinction by code
architecturedesign-patternsadapter
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