notes

Python concurrency · the series

01 The GIL is Not Your Enemy Refcounting, the 5ms handoff, and what the lock actually protects.
02 The Loop is the Trick epoll, coroutines, _run_once, and the Task spine that drives them.
03 Asyncio Sidequests The self-pipe, signals, debug mode, asyncio.run, contextvars, uvloop.
04 The Two-Way Door Generators, send, throw, yield from, and what await desugars to.
05 Scopes and Checkpoints anyio 101 — cancel scopes, checkpoints, task groups, memory streams.
06 Two Ways to Cancel The pre-armed peek and the task group that quietly turns it into a lie.
07 Servers, in Earnest Putting the loop to work behind a real request-serving stack.

Measure the Loop, Not the Request Instrumenting asyncio: stall canary, task census, py-spy, the five metrics.
Middleware is an Onion Starlette's request stack, layer by layer, and where it leaks.
The Peek That Always Returns False Chasing SSE disconnect detection through five middleware layers.
One Loop, Twenty Milliseconds How Pipecat moves real-time audio through a dozen AI services on a single event loop — without ever blocking.
An Hour on One Loop Architecting a voice agent on Temporal: a single activity that holds an asyncio loop open for half an hour, with WebRTC and Redis bridged in.