Python is slow only when you write it slowly. These 20 production-tested techniques make your Python code dramatically faster — from profiling to vectorization to multiprocessing.

Python typing goes far beyond basic annotations. Generics, Protocol classes, TypeVar constraints, and ParamSpec let mypy catch bugs that unit tests miss entirely.

Python asyncio and threading achieve concurrency through completely different mechanisms. Real benchmarks across I/O-bound, CPU-bound, and mixed workloads reveal exactly when each approach wins.

Python dataclasses do far more than generate __init__. Field metadata, post-init processing, frozen instances, __slots__ integration, and ClassVar usage that most tutorials skip entirely.

Python's Global Interpreter Lock prevents true thread parallelism for CPU-bound code. Here's exactly why it exists, what it protects, when it hurts you, and the three ways to bypass it.

Python's __slots__ eliminates the hidden __dict__ overhead on every object instance. For classes with millions of instances, this cuts memory by 60% and speeds up attribute access by 35%.