Sylvain Wallez

Sylvain Wallez

@swallez.com

Software engineer, from big servers to tiny microcontrollers. Principal engineer at @elastic.co, member of @apache.org. Blogging (sometimes) at https://bluxte.net 🌐 Toulouse, France, Europe

1.4K followers418 following2.8K posts

Sylvain Wallez reposted

“The thing we’re doing will destroy really important stuff but don’t worry it’ll eventually get better, probably. Anyway, give us all your money.”

Matt Novak@paleofuture.bsky.social

Jason Clinton is the Deputy Chief Information Security Officer at Anthropic.

Sylvain Wallez reposted

Hier je suis intervenu dans une école, comme depuis maintenant 4 ans. C'est toujours un moment où je reçois autant que je donne, c'était encore le cas hier 🤗. Merci aux étudiant·es présent·es, c'était passionnant 🤩. Mais, car il y a un "mais" ⬇️

Sylvain Wallez reposted

Nouvelle vidéo : « Ils ont copié IBM dans le plus grand calme (clean room) » Dans cette vidéo, je vous propose de découvrir la technique de « Clean Room » utilisée et popularisée par Compaq et Phoenix pour réimplémenter le BIOS de l’IBM PC 🔗 youtu.be/epJm1LccK30

J'ai passé un très bon moment avec l'ami @emmanuelbernard.com au studio @devoxx.fr à discuter de Rust, et aussi de plein d'autres choses. Et comme il dit, on aurait pu discuter des heures 😜

Devoxx France@devoxx.fr

« Au début le compilateur est un ennemi, puis un professeur, puis un assistant. » 🦀 @swallez.com décortique Rust : borrow checker, latence sans GC et parser Parquet zéro-copie. De quoi se dérouiller les méninges ! 📺 La vidéo à voir ici : youtu.be/Kx4_k4EhSKY

The talks at #EuroRust reflect the wide variety of domains where Rust shines: network servers, high performance calculation, including on the GPU and even… Ikea lamps! Well, embedded systems, actually 😛

#EuroRust day 2. Really a great conference with in-depth topics and a great community!

EuroRust@eurorust.eu

Found Ferris outside, a bit fashionably late! 🦀 #EuroRust26 #RustLang

Sylvain Wallez reposted

No joke. I think this is the most important video I have ever seen about mobile games. This guy breaks down how this game psychologically profiles you, and makes the game harder or easier in order to show you ads

Sylvain Wallez reposted

If you enjoy working with large-scale data processing systems and you want to stay relevant, you have to learn Apache DataFusion. Slowly but surely, it's replacing many other tools. The RAD stack (Rust, Arrow, DataFusion) is the future. One example: www.datadoghq.com/blog/enginee...

datadoghq.comHow we extended Apache DataFusion to execute one query across many machines | DatadogLearn how Datadog built Distributed DataFusion to scale interactive Apache DataFusion queries across multiple machines.

Sylvain Wallez reposted

github.com/lloydmeta/st... My kid wanted to extract the different "stems" from a track (guitar, drum, vocals etc) so she could practise songs she likes, and to be able to slow it down while muting/unmuting different stems that you can download as mp3/wav. [1] #creative-coding #vibecoding #music

github.comGitHub - lloydmeta/stemyla: Music stem separator that runs in your browser via WebGPU. Vibe-coded!Music stem separator that runs in your browser via WebGPU. Vibe-coded! - lloydmeta/stemyla

Beyond Suno and generative music, the music software scene is flooded with vibecoded plugins. This post starts with a great explanation of AI-assisted coding vs vibecoding. It's all about understanding what you're doing and staying in control.

Synth Anatomy (Tom) @synthanatomy.bsky.social

Vibe coding plugins: the good, the bad, and the impact on my news coverage synthanatomy.com/2026/10/vibe... #plugins #plugin #vstplugin #musicproducer #musicproduction #synthesizer #synthanatomy

Sylvain Wallez reposted

Quand un mathématicien vous dit que l'IA a ruiné son métier et que vous lui répondez qu'il va pouvoir se concentrer sur d'autres problèmes ou des choses "plus intéressantes", vous n'écoutez pas ce qu'il vous dit. Pareil pour un informaticien, un artiste, un traducteur...

Sylvain Wallez reposted

Donc Ecosia abandonne Mistral pour des modèles chinois notamment parce que Mistral consomme de l'électricité nucléaire. Ce délire allemand continue. Plus de division. Imaginez l'argument miroir : "j'utilise pas Ecosia car éoliennes". (Et du gaz et charbon, du coup, après artifice comptable).

Sylvain Wallez reposted

Trump is a filthy bastard. His collusion with russia amounts to high treason. While Moscow continues to escalate its massacres of Ukrainians, Trump is offering criminals money. It's a strong incentive for the Ukrainians to bomb russian refineries even more—the Europeans must help them decisively.

I used this trick more than once. Very convenient when you forget your travel adapter!

Marc Thiele@marcthiele.com

Just found out that a lot of people don‘t know that you can use a ”C7 figure‑8 power cord“ with any Apple power adapter in case you forgot your travel adapter. Way cheaper to get one of those usually than a full travel adapter. #travelhacks

Sylvain Wallez reposted

RIP Margaret Hamilton, the brilliant computer scientist whose contributions to software for the Apollo Guidance Computer were absolutely crucial to the Apollo Moon landings. She also helped shape the discipline of computer engineering while at MIT's Instrumentation Lab: news.mit.edu/2026/margare...

Sylvain Wallez reposted

"The model had tried to go beyond its testing environment, but that this was expected and the company was able to prevent it". Nice. This is what doing your job correctly is about. And not "OMG OMG, look how powerful our model is, it hacked random sites on the internet! Stop us or we'll all die!"

It will be interesting to see what the Shelly product line becomes after this acquisition. Shelly is known for a combination of great quality/price ratio for devices that are very open and featured, supporting a wide range of communication protocols.

Sylvain Wallez reposted

lol one of our website designers used our organization's entire monthly claude credits yesterday and now half the company doesn't know how to do their jobs. it's october 2nd.

Sylvain Wallez reposted

The boom in Linux CVEs lately should get you thinking.

 Surely, given a finite codebase, there are also a finite number of bugs / unintended behavior, thus, a finite amount of vulnerabilities. Theoretically, a “solvable” problem. Right?

 Well…not at all actually.

Sylvain Wallez reposted

Si vous commencez le vibe coding, faites tout en Rust. Le compilateur est chiant, contraignant, il vous dit exactement ce qui ne va pas. Et c’est justement pour ça qu’un LLM peut très bien travailler avec. Épisode d’Underscore avec Micode et MatthieuLambda : youtu.be/AiytemqB_F0?...

Sylvain Wallez reposted

I will not stop reading code anytime soon. LLMs can generate code that's correct and even performant, but I frequently find it too complex. And I hate accidental complexity - it compounds very quickly and leads to cruft, bugs, and, ultimately, slow and unreliable software.

Sylvain Wallez reposted

Bon, j’ai regardé le spectacle « historique » donné au Stade de France à l’occasion de la visite du pape. Réaction et analyse d’un show qui développe une vision fantasmée et délirante de l’histoire de France et du catholicisme 1/

I don't buy DHH's claim that you don't need to read code anymore. Hey! and Campfire's rewrites in Rust are not rewrites. They're transpilations done in the best possible conditions: the Ruby code is used as a reference and they have a strong validation harness that includes the existing application.

github.comGitHub - basecamp/once-campfire-rust: ONCE Campfire in Rust: one binary, the Rails app's data, 19–44× fasterONCE Campfire in Rust: one binary, the Rails app's data, 19–44× faster - basecamp/once-campfire-rust
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Will LLMs keep using this non-idiomatic style, or will they mix in idiomatic code, which is what they've been trained on, resulting in an inscrutable mess in a code base that is already hard to read? And also, how do they approach production issues that will inevitably happen?

With a deterministic transpiler you can develop knowledge on its mechanisms or even its inner workings. With LLM-generated code you end up using the LLM to understand and fix issues. And they have a tendency to fix symptoms and avoid needed larger refactorings, resulting in more mess…

I don't buy DHH's claim that you don't need to read code anymore. Hey! and Campfire's rewrites in Rust are not rewrites. They're transpilations done in the best possible conditions: the Ruby code is used as a reference and they have a strong validation harness that includes the existing application.

github.comGitHub - basecamp/once-campfire-rust: ONCE Campfire in Rust: one binary, the Rails app's data, 19–44× fasterONCE Campfire in Rust: one binary, the Rails app's data, 19–44× faster - basecamp/once-campfire-rust

If you look at the Rust code, it's ugly and is basically Ruby's semantic model in Rust (BTW it could be 10x more efficient using idiomatic Rust). This is why it's a transpilation, similar what Facebook did with Hack for PHP (static analysis, native code generation), but done with an LLM.

So although this rewrite is successful, it raises a lot of questions on the evolution and maintenance of this code base? Nothing is said on how to add and validate new features, which is the hardest part in agentic coding.

My wife caught a germ and has completely lost her voice. She remembered we had kept our kids' Magna Doodle in the basement and uses it to "talk" to me. We didn't expect this toy to be so useful!

Dear Claude. When I'm asking for a code review, why do you report "plausible" findings that I have to ask you to confirm? Do your job thoroughly, for Token's sake!

Sylvain Wallez reposted

🎉 Nouveau sujet ! Bienvenue à Guillaume Rodriguez au #DevFestToulouse 🚀 🎤 Doom tournait sur un 486. Votre app rame sur un MacBook Pro. (Conférence) RDV le 19 novembre !

Sylvain Wallez reposted

Today we're introducing Cloud Sandboxes: same microVM isolation as Docker Sandboxes on your laptop, same CLI, always-on Docker-managed compute. Close your laptop. Keep the agent running. Move between local and cloud with one command. $250 credit for new accounts: docker.com/sbx-promo

Je pense que ça mérite une consultation de l'ensemble de la francophonie. Vous en pensez quoi ? D'autres propositions ? 🤣