#threads

6 threads interview questions, asked at Nuro, Uber, Google and 1 more company. Last asked Aug 2026.

Two threads updating a shared counter with different stop conditionsCodingStart two threads that both update a shared counter. One stops when the counter reaches 10 and returns a snapshot of it; the other stops after one second and returns its snapshot…
Last asked Aug 2026
Video playback loop at 25 frames per secondCodingYou get a VideoPlayer with a Read() that returns the next frame and a call that renders a frame. Write the playback loop: frames must be shown at a steady 25 frames per second…
Last asked Aug 2026
Build your own CompletableFutureCodingImplement a small version of CompletableFuture: a result that some thread completes later, that other threads can wait on, and that can be chained with callbacks. Then use it to…
Last asked Jun 2026
Thread-safe scheduler for periodic jobsCodingWrite a scheduler that runs functions periodically, at a frequency such as 50 Hz, with schedule and cancel. One thread runs the jobs while other threads may add or cancel them at…
Last asked May 2026
Deduplicate concurrent downloads of the same URLCodingWrite a downloader that many threads call with URLs. Downloads of different URLs run in parallel. When several threads ask for the same URL at the same time, only one of them…
Last asked Apr 2026
Run three methods in a fixed order across threadsCodingThree methods, first(), second() and third(), are called by three different threads in any order. Make sure they always run in that order, using locks, events or semaphores.
Last asked Aug 2025