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
445 challenges matching your filters
Clear topic filter- Code AnalysisIntermediate
Password hashing choice
backendintermediate - Code AnalysisIntermediate
X-Frame-Options
backendintermediate - Code AnalysisIntermediate
Audit log entry
backendintermediate - Multiple ChoiceIntermediate
Unit Testing
backendintermediate - Multiple ChoiceIntermediate
Integration Testing
backendintermediate - Multiple ChoiceIntermediate
E2E Testing
backendintermediate - Multiple ChoiceIntermediate
Test Pyramid
backendintermediate - Multiple ChoiceIntermediate
Mocking
backendintermediate - Multiple ChoiceHard
Stub vs Mock
backendhard - Multiple ChoiceBeginner
Assertions
backendbeginner - Multiple ChoiceIntermediate
Test Coverage
backendintermediate - Multiple ChoiceIntermediate
TDD Cycle
backendintermediate - Multiple ChoiceIntermediate
API Testing
backendintermediate - Multiple ChoiceIntermediate
Fixtures
backendintermediate - Multiple ChoiceIntermediate
Snapshot Testing
backendintermediate - Multiple ChoiceIntermediate
Regression Testing
backendintermediate - Multiple ChoiceIntermediate
Smoke Tests
backendintermediate - Multiple ChoiceIntermediate
Isolation in Tests
backendintermediate - Code AnalysisBeginner
Unit test example
backendbeginner - Code AnalysisIntermediate
Mock function
backendintermediate - Code AnalysisIntermediate
Integration test scope
backendintermediate - Code AnalysisIntermediate
Coverage percentage
backendintermediate - Code AnalysisBeginner
Assertion failure
backendbeginner - Code AnalysisIntermediate
TDD red-green-refactor
backendintermediate - Code AnalysisIntermediate
Test isolation issue
backendintermediate
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.