Sylvain Wallez
@swallez.com
Software engineer, from big servers to tiny microcontrollers. Member of The ASF, working at @rerun.io, ex-Elastic. Blogging (sometimes) at https://bluxte.net
🌐 Toulouse, France, Europe
🌐 Toulouse, France, Europe
Reposted by Sylvain Wallez
Reposted by Sylvain Wallez
November 22, 2025 at 7:49 AM
That feeling when everything finally falls into place in your code after hours of massaging and refactoring and unit tests are green…
a woman wearing a purple shirt and overalls is sitting in a chair with her eyes closed
Alt: Bliss
media.tenor.com
November 22, 2025 at 10:30 AM
That feeling when everything finally falls into place in your code after hours of massaging and refactoring and unit tests are green…
This meme is getting out of hand, but it's actually not far from reality 🤣
November 21, 2025 at 12:13 PM
This meme is getting out of hand, but it's actually not far from reality 🤣
Reposted by Sylvain Wallez
This is *NEAT*.
I've published a blog post here, with implementation details and metrics:
recursion.wtf/posts/detect/
this may not come as a surprise, but it not spawning a new process via `-exec` for every file or running multiple `xargs` passes makes everything significantly faster
recursion.wtf/posts/detect/
this may not come as a surprise, but it not spawning a new process via `-exec` for every file or running multiple `xargs` passes makes everything significantly faster
November 19, 2025 at 1:44 AM
This is *NEAT*.
Reposted by Sylvain Wallez
#rustlang hot take: We should rename .unwrap() to .or_panic(). (And .expect() to .or_panic_with().) "Unwrap" is a terrible name for the panicking function, especially since we also have things like .unwrap_or() and .unwrap_or_default() which never panic.
November 19, 2025 at 7:32 AM
#rustlang hot take: We should rename .unwrap() to .or_panic(). (And .expect() to .or_panic_with().) "Unwrap" is a terrible name for the panicking function, especially since we also have things like .unwrap_or() and .unwrap_or_default() which never panic.
Cloudflare's outage was caused by an 'unwrap()' call in Rust code, that panics if a Result isn't a success. Don't blame Rust: it's a case of "should never happen", explicitly written in the code, which could have resulted in memory corruption in other languages. blog.cloudflare.com/18-november-...
Cloudflare outage on November 18, 2025
Cloudflare suffered a service outage on November 18, 2025. The outage was triggered by a bug in generation logic for a Bot Management feature file causing many Cloudflare services to be affected.
blog.cloudflare.com
November 19, 2025 at 7:47 AM
Cloudflare's outage was caused by an 'unwrap()' call in Rust code, that panics if a Result isn't a success. Don't blame Rust: it's a case of "should never happen", explicitly written in the code, which could have resulted in memory corruption in other languages. blog.cloudflare.com/18-november-...
Working with Apache Arrow at a low level, creating record batches from scratch, triggers my obsession for performance and memory frugality 😅
The arrow-rs library has convenience builders, but they come at a cost with reallocations and copies. Using lower-level buffers unleashes the raw power ⚡
The arrow-rs library has convenience builders, but they come at a cost with reallocations and copies. Using lower-level buffers unleashes the raw power ⚡
November 18, 2025 at 5:12 PM
Working with Apache Arrow at a low level, creating record batches from scratch, triggers my obsession for performance and memory frugality 😅
The arrow-rs library has convenience builders, but they come at a cost with reallocations and copies. Using lower-level buffers unleashes the raw power ⚡
The arrow-rs library has convenience builders, but they come at a cost with reallocations and copies. Using lower-level buffers unleashes the raw power ⚡
Reposted by Sylvain Wallez
Part IV: "The Developer's Journey" 🧵
I learned programming by doing boring work. AWT to Swing migrations. PHP CRUD sites at night while doing my PhD.
The tedium was the tuition.
Today that work takes seconds with an LLM.
So how do juniors learn?
lostinbrittany.dev/en/developer...
I learned programming by doing boring work. AWT to Swing migrations. PHP CRUD sites at night while doing my PhD.
The tedium was the tuition.
Today that work takes seconds with an LLM.
So how do juniors learn?
lostinbrittany.dev/en/developer...
LostInBrittany's tech blog
LostInBrittany's tech blog, reborn... again...
lostinbrittany.dev
November 17, 2025 at 6:47 PM
Part IV: "The Developer's Journey" 🧵
I learned programming by doing boring work. AWT to Swing migrations. PHP CRUD sites at night while doing my PhD.
The tedium was the tuition.
Today that work takes seconds with an LLM.
So how do juniors learn?
lostinbrittany.dev/en/developer...
I learned programming by doing boring work. AWT to Swing migrations. PHP CRUD sites at night while doing my PhD.
The tedium was the tuition.
Today that work takes seconds with an LLM.
So how do juniors learn?
lostinbrittany.dev/en/developer...
The Rust code generated by Prost from protobuf declarations could really be more ergonomic. Having spent a couple of years writing code generators with a strong focus on developer experience, this is starting to itch. I don't have time for it now though… #RustLang
November 17, 2025 at 8:31 AM
The Rust code generated by Prost from protobuf declarations could really be more ergonomic. Having spent a couple of years writing code generators with a strong focus on developer experience, this is starting to itch. I don't have time for it now though… #RustLang
Reposted by Sylvain Wallez
Un grand merci à toutes les personnes qui sont venues voir ma keynote sur comment nous avons transformé les Restos du Coeur en Cloud Provider au @capitoledulibre.org, les slides sont ⬇️
November 15, 2025 at 3:32 PM
Un grand merci à toutes les personnes qui sont venues voir ma keynote sur comment nous avons transformé les Restos du Coeur en Cloud Provider au @capitoledulibre.org, les slides sont ⬇️
Deuxième conférence de la semaine, Apache Arrow au @capitoledulibre.org ! Moins de monde qu'à la keynote de @devfesttoulouse.fr, mais beaucoup de questions très pertinentes !
November 15, 2025 at 5:00 PM
Deuxième conférence de la semaine, Apache Arrow au @capitoledulibre.org ! Moins de monde qu'à la keynote de @devfesttoulouse.fr, mais beaucoup de questions très pertinentes !
Reposted by Sylvain Wallez
Yesterday, we gave a talk about our craziest automations with @home-assistant.io at @devfesttoulouse.fr with @swallez.com @wanoo.me and @mathieupassenaud.bsky.social and the amount of people who raised their hands when asked 'Who has Home Assistant running at home?' was really impressive 🤩
November 14, 2025 at 7:57 PM
Yesterday, we gave a talk about our craziest automations with @home-assistant.io at @devfesttoulouse.fr with @swallez.com @wanoo.me and @mathieupassenaud.bsky.social and the amount of people who raised their hands when asked 'Who has Home Assistant running at home?' was really impressive 🤩
Reposted by Sylvain Wallez
I finally finished a side project, thanks to @GitHubCopilot.
Built a small PWA to manage my gift cards: barcode display, balance tracking, etc.
The trick? Assign issues to Copilot and mention it to rework PRs.
Full story 👉 blog.sunix.org/articles/how...
Built a small PWA to manage my gift cards: barcode display, balance tracking, etc.
The trick? Assign issues to Copilot and mention it to rework PRs.
Full story 👉 blog.sunix.org/articles/how...
Building a Gift Card Management App with GitHub Copilot: My First Completed Side Project
Like many developers, my life is littered with unfinished side projects. But this time was different. This time, I had GitHub Copilot as my coding companion,...
blog.sunix.org
November 14, 2025 at 3:28 PM
I finally finished a side project, thanks to @GitHubCopilot.
Built a small PWA to manage my gift cards: barcode display, balance tracking, etc.
The trick? Assign issues to Copilot and mention it to rework PRs.
Full story 👉 blog.sunix.org/articles/how...
Built a small PWA to manage my gift cards: barcode display, balance tracking, etc.
The trick? Assign issues to Copilot and mention it to rework PRs.
Full story 👉 blog.sunix.org/articles/how...
Immense respect pour Olivier qui a fait une super présentation malgré un contexte technique plus que difficile. Bravo et merci ! 👏
Le dieu de la technique était contre nous. Pas de vidéoprojection/slides pendant près de 50% de la keynote, perte de l'audio/micro, je suis resté en mode père castor, au talent 😂😂
Merci tout de même aux attendees et à @devfesttoulouse.fr pour leur attention malgré l'adversité 😅
Merci tout de même aux attendees et à @devfesttoulouse.fr pour leur attention malgré l'adversité 😅
Allez, on se retrouve tout à l'heure pour la conférence d'ouverture de @devfesttoulouse.fr avec mon talk « Another World, une belle leçon d'architecture logicielle » #DevFestToulouse
November 14, 2025 at 8:25 AM
Immense respect pour Olivier qui a fait une super présentation malgré un contexte technique plus que difficile. Bravo et merci ! 👏
Reposted by Sylvain Wallez
Quand la domotique automatise l’inutile ! 😅
Bravo à @swallez.com @mathieupassenaud.bsky.social @wanoo.me et le reste de la team pour cette belle conf de clôture du @devfesttoulouse.fr
Bravo à @swallez.com @mathieupassenaud.bsky.social @wanoo.me et le reste de la team pour cette belle conf de clôture du @devfesttoulouse.fr
November 13, 2025 at 4:47 PM
Quand la domotique automatise l’inutile ! 😅
Bravo à @swallez.com @mathieupassenaud.bsky.social @wanoo.me et le reste de la team pour cette belle conf de clôture du @devfesttoulouse.fr
Bravo à @swallez.com @mathieupassenaud.bsky.social @wanoo.me et le reste de la team pour cette belle conf de clôture du @devfesttoulouse.fr
Reposted by Sylvain Wallez
If I were you I wouldn't wait too much to get in touch with Andres!
Hi everyone! An ongoing reorganization at my current employer has prompted me to seek for a new role and would appreciate your support.
I'm open to remote (anywhere) and hybrid roles in Switzerland. I have 25+ years experience as a software developer, 8 as devrel www.linkedin.com/posts/aalmir...
I'm open to remote (anywhere) and hybrid roles in Switzerland. I have 25+ years experience as a software developer, 8 as devrel www.linkedin.com/posts/aalmir...
#opensource #opentowork | Andres Almiray
Hi everyone! An ongoing reorganization at my current employer has prompted me to seek for a new role and would appreciate your support.
I'm open to remote (anywhere) and hybrid roles in Switzerland (...
www.linkedin.com
November 12, 2025 at 7:18 AM
If I were you I wouldn't wait too much to get in touch with Andres!
Reposted by Sylvain Wallez
Impatient de participer jeudi prochain à #DevFest Toulouse pour la première fois et de montrer comment transformer des QR Codes en œuvres d’art grâce à l’IA.
Et comme dirait le stade: « Qui ne saute pas, n’est pas… » 😉
#TechAtWorldline
Et comme dirait le stade: « Qui ne saute pas, n’est pas… » 😉
#TechAtWorldline
November 12, 2025 at 7:59 AM
Impatient de participer jeudi prochain à #DevFest Toulouse pour la première fois et de montrer comment transformer des QR Codes en œuvres d’art grâce à l’IA.
Et comme dirait le stade: « Qui ne saute pas, n’est pas… » 😉
#TechAtWorldline
Et comme dirait le stade: « Qui ne saute pas, n’est pas… » 😉
#TechAtWorldline
Reposted by Sylvain Wallez
On se retrouve au DevFest Toulouse demain, où je donnerai mon talk : « Another World, une belle leçon d’architecture logicielle » en keynote d'ouverture 🔥
Un talk entremêlé de nostalgie et de technique pure, on va passer un très bon moment 🫶 @devfesttoulouse.fr
Un talk entremêlé de nostalgie et de technique pure, on va passer un très bon moment 🫶 @devfesttoulouse.fr
November 12, 2025 at 6:55 AM
On se retrouve au DevFest Toulouse demain, où je donnerai mon talk : « Another World, une belle leçon d’architecture logicielle » en keynote d'ouverture 🔥
Un talk entremêlé de nostalgie et de technique pure, on va passer un très bon moment 🫶 @devfesttoulouse.fr
Un talk entremêlé de nostalgie et de technique pure, on va passer un très bon moment 🫶 @devfesttoulouse.fr
Reposted by Sylvain Wallez
PSA: tips to protect yourself from scams on Signal.
Every major comms platform has to contend w phishing, impersonation, & scams. Sadly.
Signal is major, and as we've grown we've heard about more of these attacks--scammy people pretending to be something or someone to trick and abuse others. 1/
Every major comms platform has to contend w phishing, impersonation, & scams. Sadly.
Signal is major, and as we've grown we've heard about more of these attacks--scammy people pretending to be something or someone to trick and abuse others. 1/
November 11, 2025 at 6:13 PM
PSA: tips to protect yourself from scams on Signal.
Every major comms platform has to contend w phishing, impersonation, & scams. Sadly.
Signal is major, and as we've grown we've heard about more of these attacks--scammy people pretending to be something or someone to trick and abuse others. 1/
Every major comms platform has to contend w phishing, impersonation, & scams. Sadly.
Signal is major, and as we've grown we've heard about more of these attacks--scammy people pretending to be something or someone to trick and abuse others. 1/
Reposted by Sylvain Wallez
200 heures de préparation pour 45 minutes de présentation 📜
contretemps.azeau.com/post/200-heu...
contretemps.azeau.com/post/200-heu...
200 heures de préparation pour 45 minutes de présentation
Ça y est. Je suis prêt. Ou presque. J'ai tout fait pour.
Dans deux jours, c'est le DevFest Toulouse et j'y proposerai une expérience que je crois être inédite, …
contretemps.azeau.com
November 11, 2025 at 4:15 PM
200 heures de préparation pour 45 minutes de présentation 📜
contretemps.azeau.com/post/200-heu...
contretemps.azeau.com/post/200-heu...
I recently switched to a MacBook Pro with an M4 Max processor. It's meant for speed and the default energy settings reflect this, being "automatic" even in battery mode. If you care more about your battery life than performance, make sure you select "Low power mode" when running on battery.
November 11, 2025 at 10:24 AM
I recently switched to a MacBook Pro with an M4 Max processor. It's meant for speed and the default energy settings reflect this, being "automatic" even in battery mode. If you care more about your battery life than performance, make sure you select "Low power mode" when running on battery.
Reposted by Sylvain Wallez
Dernière heures avant la fermeture de la billeterie ⏰
1100 participants sont prévus !
Allons nous faire sold out cette année ? Dépêchez-vous pour prendre vos places : buff.ly/Wj49RJt
Fermeture de la billeterie Dimanche 9 Novembre
1100 participants sont prévus !
Allons nous faire sold out cette année ? Dépêchez-vous pour prendre vos places : buff.ly/Wj49RJt
Fermeture de la billeterie Dimanche 9 Novembre
November 7, 2025 at 6:00 PM
Dernière heures avant la fermeture de la billeterie ⏰
1100 participants sont prévus !
Allons nous faire sold out cette année ? Dépêchez-vous pour prendre vos places : buff.ly/Wj49RJt
Fermeture de la billeterie Dimanche 9 Novembre
1100 participants sont prévus !
Allons nous faire sold out cette année ? Dépêchez-vous pour prendre vos places : buff.ly/Wj49RJt
Fermeture de la billeterie Dimanche 9 Novembre
Is it just me or has the hype around MCP already faded away? Is it because it hasn't lived up to its promise, or is it already boring tech? What's your point of view?
November 7, 2025 at 10:30 AM
Is it just me or has the hype around MCP already faded away? Is it because it hasn't lived up to its promise, or is it already boring tech? What's your point of view?
Je cause dans le poste avec @wilda.bsky.social et @aurelievache.bsky.social ! J'y raconte entre autres mes aventures passées et présentes, avec une grosse section sur la création de OVH Toulouse, et bien évidemment un passage sur les sangliers toulousains ! 🐗
Le dernier tranches de tech avec @swallez.com est disponible 🥳.
Pour l'écouter cela se passe ici 🎧 : smartlink.ausha.co/tranches-de-...
Encore merci @swallez.com pour ta participation et @aurelievache.bsky.social pour ta fidèle présence.
Et merci #OVHcloud de rendre ça possible 🫶.
Pour l'écouter cela se passe ici 🎧 : smartlink.ausha.co/tranches-de-...
Encore merci @swallez.com pour ta participation et @aurelievache.bsky.social pour ta fidèle présence.
Et merci #OVHcloud de rendre ça possible 🫶.
Tranches de Tech 22 - L'homme qui murmurait à l'oreille des sangliers
Présentation de Sylvain
Rerun.io (http://Rerun.io)
Slides Camping des Speakers (https://docs.google.com/presentation/d/e/2PACX-1vRkiYn4Dg7R7pOFPkpYrCaJE6jdUwxbUSeC92OMY5OFDnAD7VMuAT1oap0NAltVcntyDuVJo...
smartlink.ausha.co
November 4, 2025 at 11:20 AM
Je cause dans le poste avec @wilda.bsky.social et @aurelievache.bsky.social ! J'y raconte entre autres mes aventures passées et présentes, avec une grosse section sur la création de OVH Toulouse, et bien évidemment un passage sur les sangliers toulousains ! 🐗