5 synchronization interview questions, asked at Apple, Tesla, Uber. Last asked Aug 2026.
Reusable cyclic barrierCodingImplement a cyclic barrier for a fixed number of threads (parties). Each thread calls wait() at a sync point; the call blocks until all parties have called it in this round, then…
Last asked Aug 2026
Implement a mutex without built-in locksCodingImplement a mutual-exclusion lock with lock() and unlock(). You may not use any lock, mutex, semaphore, monitor or condition variable from the language or a library: the point is…
Building H2OCodingThreads keep arriving, each carrying one atom: hydrogen (H) or oxygen (O). Each thread must wait until it can be part of a water molecule, then release its atom. Make sure that…
Last asked Aug 2025
Run three methods in a fixed order across threadsCodingImplement a class with three methods, alpha(), beta() and gamma(). Three different threads call them, one method each, and may start in any order. The output must still be A, B…
Last asked Aug 2025
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Synchronization interview questions · Land the Lab