Your question is Race Conditions in Multi-Threading. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How would you handle race conditions in a multi-threaded application?
Explain how you would identify whether the problem is caused by unsafe mutation, missing visibility, or incorrect operation ordering. Compare appropriate Java concurrency mechanisms, such as synchronized, ReentrantLock, AtomicInteger, volatile, and ConcurrentHashMap, and describe how you would test the fix.
Keep the answer focused on Java and the JVM, including the trade-offs between coordination, performance, and correctness.