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.
Filter by type
Filter by difficulty
Popular topics
5 challenges matching your filters
Clear topic filter- Multiple ChoiceIntermediate
Read-heavy vs write-heavy design
system-designcapacity-estimationdatabases - Code AnalysisIntermediate
Implicit type cast kills index
system-designdatabasesindexes - Code AnalysisIntermediate
Full table lock from a long transaction
system-designdatabasesconcurrency - Code AnalysisIntermediate
Deadlock from lock ordering
system-designdatabasesconcurrency - Code AnalysisIntermediate
Selective column over-fetch
system-designdatabasesperformance
Practice now, dominate the arena
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.