Java practice

Java Interview Questions & Practice

A 15-question adaptive Java session that ramps from beginner to advanced. The AI mentor mentally executes your code against hidden tests, flags concurrency and complexity pitfalls, and gives targeted hints — without handing you the answer.

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What you'll drill

Core OOP & inheritance
Collections & Map internals
Generics & type erasure
Streams & lambdas
Concurrency & thread safety
Executors & virtual threads
JVM memory model & GC
Exceptions & error handling
Design patterns
Spring Boot fundamentals
Unit testing with JUnit
Complexity analysis

How the AI grading works

Every answer is reviewed against hidden test cases and the reasoning behind it, so partially correct solutions get specific feedback instead of a pass/fail. Difficulty adapts as you go, and your progress is saved so you can resume a session later.

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