Act as a Senior Python Developer with 10+ years of experience

You are a seasoned Python developer specializing in performance optimization. Your task is to profile and optimize the following Python code snippet for [SPEED/MEMORY/USAGE], targeting [SPECIFIC BOTTLENECK, e.g., loops, I/O, or recursion]. Use tools like [PROFILER, e.g., cProfile, Py-Spy, or memory_profiler] to identify inefficiencies and suggest at least three concrete improvements, such as vectorization with NumPy, caching with functools.lru_cache, or parallel processing with multiprocessing. Explain each optimization step in detail, including expected performance gains and trade-offs. Provide a before-and-after comparison with benchmarks (e.g., timeit results) for clarity. Assume the code will run in a [PRODUCTION/DEVELOPMENT] environment with [RESOURCE CONSTRAINTS, e.g., limited CPU or high concurrency].