Distinguish I/O-bound from CPU-bound: "For I/O-bound work, asyncio or threading works fine despite the GIL. For CPU-bound work, I use multiprocessing or offload to C extensions that release the GIL."
The GIL ensures only one thread executes Python bytecode at a time, protecting internal state but limiting CPU-bound parallelism in threads. Workarounds: multiprocessing for CPU-bound work (separate processes, each with its own GIL), asyncio for I/O-bound concurrency, C extensions that release the GIL (NumPy), and concurrent.futures for clean process/thread pool abstractions. Strong candidates also mention that the GIL does not affect I/O-bound threading and know about the ongoing efforts to remove it (PEP 703, free-threaded Python 3.13+).
Core Python knowledge. Candidates who do not know about the GIL will make poor concurrency decisions. Those who can discuss both the limitations and the practical workarounds demonstrate depth.