Antonio Cuni
antocuni.bsky.social
Antonio Cuni
@antocuni.bsky.social
SPy creator, HPy founder, PyPy core dev, PyScript core dev, doing Python, compilers and WASM stuff at @anacondainc.bsky.social

Also on:
- github.com/antocuni
- https://mastodon.social/@antocuni
- https://twitter.com/antocuni
After weeks of procrastination, I finally wrote the first post in a series explaining SPy.
This one focuses on why Python is slow—the gap between what the language allows and how it’s used in practice—and hints at how SPy aims to fix it:
antocuni.eu/2025/10/29/i...
Inside SPy, part 1: Motivations and Goals - Antonio Cuni's blog
Antonio Cuni's blog
antocuni.eu
October 29, 2025 at 4:22 PM
The SPy project is kicking off community calls! 🎙️

Join us tomorrow (Oct 7th, 17:30 CEST) on Discord to chat, ask questions, and meet other SPy folks. Everyone’s welcome! 💚 🥸

Discord link: discord.gg/ZN4afjvq?eve...

Google calendar link: lnkd.in/d3U62QNn
Join the SPy lang Discord Server!
Check out the SPy lang community on Discord - hang out with 43 other members and enjoy free voice and text chat.
discord.gg
October 6, 2025 at 10:52 AM
Last week I was lucky to take part in the CPython Core Dev Sprint.
This is a summary of what I did, including an annotated and extended version of my talk on tracing JITs in real-world Python scenarios, plus some comparisons between PyPy’s JIT and CPython’s new JIT.

👉 antocuni.eu/2025/09/24/t...
Tracing JITs in the real world @ CPython Core Dev Sprint
My experience at the CPython Core Dev Sprint
antocuni.eu
September 24, 2025 at 2:55 PM
Accessing `obj.x` in Python might look trivial — but under the hood lies a surprisingly intricate chain of logic.

I wrote an annotated walkthrough of the CPython source code that makes it all happen:

antocuni.eu/2025/08/25/i...
Inside CPython's attribute lookup - Antonio Cuni's blog
antocuni.eu
August 25, 2025 at 1:00 PM
🛑⚠️ Claude code modified my .bashrc without asking? ⚠️🛑

It seems to that during an automatic update, claude sneakily modified my ~/.bashrc to remove an alias to itself.

I didn't ask my permission, it didn't notify me of the change.

I find it completely unacceptable.

antocuni.eu/2025/07/07/c...
Claude code modified my .bashrc without asking? - Antonio Cuni's blog
antocuni.eu
July 7, 2025 at 10:20 PM
Yesterday I talked about SPy at @pyconit.bsky.social
Links to slides & videos here:
antocuni.eu/2025/05/31/s...
SPy @ PyCon IT 2025
Slides of the talk
antocuni.eu
May 31, 2025 at 5:43 PM
My language is brand new and experimental, but they already named a museum after it
github.com/spylang/spy
May 23, 2025 at 1:31 PM
Wow, I'm at the same time happy, surprised and honored that my PyCon US talk about SPy (github.com/spylang/spy)
made the top 10
March 19, 2025 at 12:02 AM
I'm having mixed results with claude code. It seems very good at "easy tasks", but the most annoying thing is that it has the tendency to not follow my instructions and do "what it wants".

TL;DR: I put instructions in `CLAUDE.md` but it tends to forget about them:

antocuni.eu/2025/03/16/t...
Tales with claude code: how to make it behave? - Antonio Cuni's blog
antocuni.eu
March 16, 2025 at 5:14 PM
I wrote a small tool to automatically record all my "claude code" sessions and export them into easily shareable HTML:
github.com/antocuni/cla...

Example log:
antocuni.github.io/files/claude...
GitHub - antocuni/claude-logging: Automatically log claude sessions, and export them to HTML
Automatically log claude sessions, and export them to HTML - antocuni/claude-logging
github.com
March 12, 2025 at 4:53 PM
Last week @lukasz.langa.pl and Hoot Chatham visited me on the Italian Alps for a week of hacking and winter sports. This is the report:
antocuni.eu/2025/02/26/o...
SPOILER ALERT: it contains tons of PRs to CPython, Pyodide and SPy.
Over the Clouds: CPython, Pyodide, and SPy
A week of hacking and winter sports in Cervinia
antocuni.eu
February 26, 2025 at 6:12 PM
Reposted by Antonio Cuni
Fast on the heels of the last release, I have published a PyPy v7.3.19 bug-fix release with PyPy2.7, PyPY3.10 and a beta-quality PyPy3.11. Please try it out! The complete release note is at doc.pypy.org/en/latest/re...
PyPy v7.3.19: release of python 2.7, 3.10 and 3.11 beta, released 2025-02-26 — PyPy documentation
doc.pypy.org
February 26, 2025 at 12:26 PM
Reposted by Antonio Cuni
I spent last week in Valtournenche with @antocuni.bsky.social and Hood Chatham and managed to use SPy to accelerate my #Python code in the browser. It's too early for general adoption, but not too early to get excited!

lukasz.langa.pl/f37aa97a-9ea...
A peek into a possible future of Python in the browser - Łukasz Langa
My Python code was too slow, so I made it faster with Python. For some definition of “Python”.
lukasz.langa.pl
February 24, 2025 at 7:10 PM
Reposted by Antonio Cuni
SPy retreat in #Cervinia with @antocuni.bsky.social and Hood Chatham.
February 17, 2025 at 3:30 PM