#561: TonIO, a Multi-threaded Async Runtime for Python

How many cores does your machine have, 10, 18? Your async Python code uses just one of them. That isn't a bug in asyncio. That's the design, and optimizing event loops to be faster by 20% doesn't change it. So Giovanni Barillari started over. Joe is the creator of Granian, the Rust-based server that powers Talk Python. His new project is TonIO, an async runtime written from scratch for free-threaded Python. Real threads, a handful of primitives instead of asyncio's pile of them, and it flat out refuses to start if the GIL is on. Episode sponsors Sentry Error Monitoring, Code talkpython26 Python in Production Talk Python Courses Links from the show Guest Giovanni Barillari: github.com Granian: github.com Hyper: github.com Free threaded Python: docs.python.org Sort of: labs.quansight.org did a whole course: training.talkpython.fm uvloop: github.com rloop: github.com TonIO: github.com your EuroPython 2026 talk: www.youtube.com Michael's Cutting Python Web App Memory Over 31% Article: mkennedy.codes Watch this episode on YouTube: youtube.com Episode #561 deep-dive: talkpython.fm/561 Episode transcripts: talkpython.fm Theme Song: Developer Rap 🥁 Served in a Flask 🎸: talkpython.fm/flasksong ---== Don't be a stranger ==--- YouTube: youtube.com/@talkpython Bluesky: @talkpython.fm Mastodon: @[e-mail] X.com: @talkpython Michael on Bluesky: @mkennedy.codes Michael on Mastodon: @[e-mail] Michael on X.com: @mkennedy