Pierre Chapuis
catwell.info
Pierre Chapuis
@catwell.info
https://catwell.info

Software @ https://finegrain.ai/. AI and Distributed Systems.

Known as @pchapuis or @catwell elsewhere.
@l-avrot.bsky.social MACI m'a tué avec le fail sur ta recommandation musicale 😂

(Ils ont mis ça : www.youtube.com/watch?v=FG2w...)
Hellstorm - Drink The Blood of Angels (Oficial Vídeo)
YouTube video by Hellstorm Oficial
www.youtube.com
October 31, 2025 at 1:49 PM
Pierre's recent posts are invaluable, this one is no exception :)

I have always thought building on top of a dual real / simulated abstraction like this is incredibly valuable. I've done something similar on a much smaller scale over 15 years ago [...]
Did you know #FoundationDB's simulator randomly swaps disks between machines on reboot? 75% of the time. On purpose.

I wrote how this works: interface swapping, BUGGIFY chaos injection, and how we use it at @clever-cloud.com to build Materia.

pierrezemb.fr/posts/diving...
Diving into FoundationDB's Simulation Framework
How FoundationDB achieves legendary reliability through deterministic simulation, interface swapping, and one trillion CPU-hours of testing
pierrezemb.fr
October 31, 2025 at 8:31 AM
Writing working naive code and asking an agent to write an optimized version can be an incredibly effective approach.
October 21, 2025 at 3:16 PM
Reposted by Pierre Chapuis
I just published "A Practical Guide to Application Metrics: Where to Put Your Instrumentation" 📊

Learn where to instrument your apps with 5 essential metric types and real-world patterns that actually help during on-call incidents.

pierrezemb.fr/posts/practi...
A Practical Guide to Application Metrics: Where to Put Your Instrumentation
A comprehensive guide on where and how to instrument metrics in your applications, covering everything from API endpoints to background jobs
pierrezemb.fr
September 24, 2025 at 1:01 PM
"This year we are slightly changing the way we make the choices of which devrooms we select. [...] As an example, we want some more weird and wonderful Plan9 ecosystem devrooms." 💚 fosdem.org/2026/news/20...
FOSDEM 2026 - FOSDEM 2026 Call for Participation
fosdem.org
September 26, 2025 at 7:38 AM
I will be at AI Engineer Paris tomorrow afternoon, hosting Discovery Track 1. Come say hi at the afterparty!
September 23, 2025 at 1:32 PM
We (Finegrain) trained a rank 8 Flux Kontext LoRA to place objects in scene images.

Weights: huggingface.co/finegrain/fi...
Demo space: huggingface.co/spaces/fineg...
Blog post: blog.finegrain.ai/posts/produc...
finegrain/finegrain-product-placement-lora · Hugging Face
We’re on a journey to advance and democratize artificial intelligence through open source and open science.
huggingface.co
September 12, 2025 at 12:05 PM
Reposted by Pierre Chapuis
Heureuse d’annoncer mon nouveau poste de professeure en psychologie du numérique !

Encore des années à étudier vos likes, vos scrolls et vos nuits volées par les écrans… mais c’est pour la science.
September 1, 2025 at 8:16 AM
Something that has not changed in 15 years of Machine Learning: people still can't figure out conventions. For instance, passing timesteps in [0, 1], [0, 999] increasing and decreasing in the *same* diffusion codebase (all with the same type and argument name)...
August 27, 2025 at 11:45 AM
<rant>

I get that you want to write your website from scratch and keep it lightweight. I really do! I do that too!

But *please* add a feed of any kind! Atom, RSS, JSON Feed... Anything is fine, just have one. There's so much good content out there I'm sad not being able to subscribe too.

</rant>
August 27, 2025 at 7:44 AM
Two new posts today (yes, I am on holiday!)

- A short list of strong beliefs blog.separateconcerns.com/2025-08-24-b...

- A "what work I want" post inspired by Sean Goedecke blog.separateconcerns.com/2025-08-24-w...
Beliefs
List of things I believe.
blog.separateconcerns.com
August 24, 2025 at 2:10 PM
Reposted by Pierre Chapuis
Prôner des vérifications d’accès aux réseaux sociaux avant 15 ans, attention à ce qu’on souhaite ...
Bluesky est indisponible dans l’état du Mississippi car il n’a pas les moyens de mettre en place la vérification d’âge exigée et dénonce un loi liberticide. Voilà quand ce n’est pas proportionné.
bsky.app Bluesky @bsky.app · Aug 22
Unfortunately, Bluesky is unavailable in Mississippi right now, due to a new state law that requires age verification for all users.

While intended for child safety, we think this law poses broader challenges & creates significant barriers that limit free speech & harm smaller platforms like ours.
August 23, 2025 at 9:07 AM
One more "Thoughts & Links" blog post: blog.separateconcerns.com/2025-08-21-t...
Thoughts & Links 12
Assorted thoughts for the last 6 months.
blog.separateconcerns.com
August 21, 2025 at 3:12 PM
If you want to listen to *actual* experts talk about what language models can do in a way mostly accessible to the general public, this is a great video: www.youtube.com/watch?v=fGKN...
Interpretability: Understanding how AI models think
YouTube video by Anthropic
www.youtube.com
August 17, 2025 at 2:07 PM
Trains are the best place to read papers 😅
August 9, 2025 at 2:41 PM
Just blogged: How I use AI coding tools (in summer 2025)

blog.separateconcerns.com/2025-08-08-a...
How I use AI coding tools (in summer 2025)
I use Copilot for completion, Claude Code, and I try to avoid Lovable.
blog.separateconcerns.com
August 8, 2025 at 7:57 PM
Everyone is looking at gpt-oss, I'm looking at Genie 3...
August 5, 2025 at 8:09 PM
The day I got custom table legs, and what it taught me about support (by Julien Danjou)

julien.danjou.info/p/the-day-i-...
The Day I Got Custom Table Legs
What It Taught Me About Support
julien.danjou.info
July 22, 2025 at 8:00 AM
Reposted by Pierre Chapuis
ln(😅) = 💧ln(😄)
July 21, 2025 at 11:09 AM
Dunning–Kruger was always a thing in programming, but with AI agents we've reached a whole new level...
July 17, 2025 at 7:28 AM
Brace yourself, Open Source slop is coming. news.ycombinator.com/item?id=4456...
Show HN: CallFS – S3-style object store in one Go binary (MIT) | Hacker News
news.ycombinator.com
July 15, 2025 at 8:15 AM
The same way we sometimes wish we could talk to a human instead of filling a broken form, we will soon wish there was an app instead of a stupid AI bot. But that will be the exception, not the norm. Most of the time the new paradigm will be better.
June 25, 2025 at 5:40 PM
Reposted by Pierre Chapuis
Ca alors, mais qui aurait pu prévoir. La surprise est la plus totale.

Encore et toujours ce problème de méthode du législateur 🇫🇷 (et de ses relais administratifs) qui depuis 2 législatures s'auto-persuade qu'on peut prendre des libertés avec le droit de l'Union quand la finalité est légitime.
Breaking🚨 : Pornhub, Youporn et Redtube de retour en France !
Ils s'appuient sur la décision de justice qui a suspendu le contrôle d'âge des internautes. Décision marquée par une grosse bourde de @rachidadati.bsky.social @linforme.com : x.com/reesmarc/sta...
www.linforme.com/tech-telecom...
:
June 20, 2025 at 7:48 AM