Python Concurrency — Junior¶

Concurrency helps a program wait for more than one thing; it does not automatically make code faster.

• Use plain synchronous code first.
• Use async def only with await-compatible I/O.
• Never call blocking I/O or CPU-heavy work directly inside an async handler.
• Protect shared mutable state and keep tasks small.

Use timeouts and tests that prove cancellation and failure behavior.