Pierre Zemb
@pierrezemb.fr
🧑💻 Staff Engineer @clever-cloud.com
🤩 Distributed and Database Systems
🚀 Co-leader Finistdevs.org
💪 Squash player
🤩 Distributed and Database Systems
🚀 Co-leader Finistdevs.org
💪 Squash player
🎄 Before heading to holidays, I wrote my 2025 year in review.
✍️ Back to engineering after 2 years of management. Built moonpool, a #FoundationDB simulation framework in #rustlang. Published 20 posts. Learned to work with LLMs. A year of going deeper.
pierrezemb.fr/posts/2025-y...
✍️ Back to engineering after 2 years of management. Built moonpool, a #FoundationDB simulation framework in #rustlang. Published 20 posts. Learned to work with LLMs. A year of going deeper.
pierrezemb.fr/posts/2025-y...
2025: A Year in Review
Reflections on returning to engineering, discovering simulation as a superpower, learning to work with LLMs, and the compounding value of years of distributed systems work.
pierrezemb.fr
December 26, 2025 at 10:01 AM
🎄 Before heading to holidays, I wrote my 2025 year in review.
✍️ Back to engineering after 2 years of management. Built moonpool, a #FoundationDB simulation framework in #rustlang. Published 20 posts. Learned to work with LLMs. A year of going deeper.
pierrezemb.fr/posts/2025-y...
✍️ Back to engineering after 2 years of management. Built moonpool, a #FoundationDB simulation framework in #rustlang. Published 20 posts. Learned to work with LLMs. A year of going deeper.
pierrezemb.fr/posts/2025-y...
🔧 I just published a blogpost about specs in the #LLM era. Model checkers like #Fizzbee work for algorithms. But for APIs and business logic? The tooling doesn't exist yet.
pierrezemb.fr/posts/specs-...
pierrezemb.fr/posts/specs-...
Specs Are Back, But We're Missing the Tools
LLMs revived specifications. Model checkers like Fizzbee work for algorithms. But for APIs and business logic? The tooling doesn't exist yet.
pierrezemb.fr
December 19, 2025 at 9:04 AM
🔧 I just published a blogpost about specs in the #LLM era. Model checkers like #Fizzbee work for algorithms. But for APIs and business logic? The tooling doesn't exist yet.
pierrezemb.fr/posts/specs-...
pierrezemb.fr/posts/specs-...
What Does a Database for SSDs Look Like? - Marc's Blog brooker.co.za/blog/2025/12...
What Does a Database for SSDs Look Like? - Marc's Blog
Maybe not what you think.
brooker.co.za
December 16, 2025 at 8:27 AM
What Does a Database for SSDs Look Like? - Marc's Blog brooker.co.za/blog/2025/12...
🧪 How do you test #rustlang code that runs on top of #FoundationDB?
✍️ I wrote about designing simulation workloads: the patterns that find real bugs, the rules you can't break, and the pitfalls
pierrezemb.fr/posts/writin...
✍️ I wrote about designing simulation workloads: the patterns that find real bugs, the rules you can't break, and the pitfalls
pierrezemb.fr/posts/writin...
Designing Rust FDB Workloads That Actually Find Bugs
Patterns and principles for writing Rust simulation workloads that catch bugs before production does.
pierrezemb.fr
December 9, 2025 at 8:00 AM
🧪 How do you test #rustlang code that runs on top of #FoundationDB?
✍️ I wrote about designing simulation workloads: the patterns that find real bugs, the rules you can't break, and the pitfalls
pierrezemb.fr/posts/writin...
✍️ I wrote about designing simulation workloads: the patterns that find real bugs, the rules you can't break, and the pitfalls
pierrezemb.fr/posts/writin...
This is an awesome podcast episode about debugging a Grown-up #ZFS Data Corruption Bug podcasts.apple.com/fr/podcast/o...
Grown-up ZFS Data Corruption Bug
Épisode de l’émission · Oxide and Friends · 26/11/2025 · 1 h 21 min
podcasts.apple.com
December 6, 2025 at 12:58 PM
This is an awesome podcast episode about debugging a Grown-up #ZFS Data Corruption Bug podcasts.apple.com/fr/podcast/o...
I think I finally have a problem where I'd genuinely feel safer writing a TLA+ spec before even touching simulation code. Time to actually learn it. #tlaplus
lamport.azurewebsites.net/video/videos...
lamport.azurewebsites.net/video/videos...
TLA+ Video Course
A Word of Warning These videos are not light entertainment. They require careful viewing and actual thinking. You may often stop a video to digest what you've just seen, and perhaps to skip back and…
lamport.azurewebsites.net
November 28, 2025 at 9:25 AM
I think I finally have a problem where I'd genuinely feel safer writing a TLA+ spec before even touching simulation code. Time to actually learn it. #tlaplus
lamport.azurewebsites.net/video/videos...
lamport.azurewebsites.net/video/videos...
Reposted by Pierre Zemb
DataFusion 51.0.0 release blog: datafusion.apache.org/blog/2025/11...
November 25, 2025 at 8:50 PM
DataFusion 51.0.0 release blog: datafusion.apache.org/blog/2025/11...
Reposted by Pierre Zemb
Hey hey! We recently tripped over a ZFS data corruption bug–introduced over 18 years ago! @bcantrill.bsky.social and I discuss with members of the Oxide team as well as Matt Ahrens, the co-inventor of ZFS.
Oxide and Friends 11/24/2025 -- A Grown-up ZFS Data Corruption Bug
YouTube video by Oxide Computer Company
youtu.be
November 25, 2025 at 11:23 PM
Hey hey! We recently tripped over a ZFS data corruption bug–introduced over 18 years ago! @bcantrill.bsky.social and I discuss with members of the Oxide team as well as Matt Ahrens, the co-inventor of ZFS.
New books to finish the year!
November 22, 2025 at 1:51 PM
New books to finish the year!
Reposted by Pierre Zemb
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 🤣
A 'small' vanilla Kubernetes install on NixOS stephank.nl/p/2025-11-17...
A 'small' vanilla Kubernetes install on NixOS
— Stéphan Kochen, 2025-11-17
stephank.nl
November 19, 2025 at 10:51 AM
A 'small' vanilla Kubernetes install on NixOS stephank.nl/p/2025-11-17...
Reposted by Pierre Zemb
D'autres meetups ont des soucis de no-show, nous on a la chance d'avoir de l'over-show ! 26 inscrits, 37 présents pour le super talk de @snicoll.be sur #spring 4.
Parce que oui, nous somme toujours un JUG, FinistJUG forever ☕️ #java #spring
Merci encore à #Zenika #Brest pour l'accueil !
Parce que oui, nous somme toujours un JUG, FinistJUG forever ☕️ #java #spring
Merci encore à #Zenika #Brest pour l'accueil !
November 13, 2025 at 6:23 PM
🤔 Have you ever wondered how #kubernetes caches #etcd?
✍️ I just published a new deep-dive into K8s watch cache: per-resource Cachers, waitUntilFreshAndBlock(), and progress notifications for quiet resources.
pierrezemb.fr/posts/diving...
✍️ I just published a new deep-dive into K8s watch cache: per-resource Cachers, waitUntilFreshAndBlock(), and progress notifications for quiet resources.
pierrezemb.fr/posts/diving...
Diving into Kubernetes' Watch Cache
Understanding how Kubernetes apiserver caches etcd, the 3-second timeout, and K8s 1.34 consistent read feature
pierrezemb.fr
November 12, 2025 at 8:13 AM
🤔 Have you ever wondered how #kubernetes caches #etcd?
✍️ I just published a new deep-dive into K8s watch cache: per-resource Cachers, waitUntilFreshAndBlock(), and progress notifications for quiet resources.
pierrezemb.fr/posts/diving...
✍️ I just published a new deep-dive into K8s watch cache: per-resource Cachers, waitUntilFreshAndBlock(), and progress notifications for quiet resources.
pierrezemb.fr/posts/diving...
TLA+ Modeling of AWS outage DNS race condition muratbuffalo.blogspot.com/2025/11/tla-...
TLA+ Modeling of AWS outage DNS race condition
On Oct 19–20, 2025, AWS’s N. Virginia region suffered a major DynamoDB outage triggered by a DNS automation defect that broke endpoint resol...
muratbuffalo.blogspot.com
November 7, 2025 at 9:06 AM
TLA+ Modeling of AWS outage DNS race condition muratbuffalo.blogspot.com/2025/11/tla-...
Async QUIC and HTTP/3 made easy: tokio-quiche is now open-source blog.cloudflare.com/async-quic-a...
Async QUIC and HTTP:3 made easy- tokio-quiche is now open-source
We’re excited to announce the open sourcing of tokio-quiche, our async QUIC library built on quiche and tokio. Relied upon in our services such as iCloud Private Relay and our next-generation…
blog.cloudflare.com
November 7, 2025 at 9:02 AM
Async QUIC and HTTP/3 made easy: tokio-quiche is now open-source blog.cloudflare.com/async-quic-a...
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...
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 30, 2025 at 8:22 AM
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...
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...
Reposted by Pierre Zemb
Digital edition of my fourth book, Crafting Engineering Strategy, is up for purchase! (Print copy should start shipping in next 2-3 weeks.) Tried to apply "Staff Engineer" formula to eng strategy topic, with a lot more editing 😂
www.amazon.com/Crafting-Eng...
www.amazon.com/Crafting-Eng...
Crafting Engineering Strategy: How Thoughtful Decisions Solve Complex Problems
Crafting Engineering Strategy: How Thoughtful Decisions Solve Complex Problems - Kindle edition by Larson, Will. Download it once and read it on your Kindle device, PC, phones or tablets. Use features like bookmarks, note taking and highlighting while reading Crafting Engineering Strategy: How Thoughtful Decisions Solve Complex Problems.
www.amazon.com
October 25, 2025 at 9:52 PM
Digital edition of my fourth book, Crafting Engineering Strategy, is up for purchase! (Print copy should start shipping in next 2-3 weeks.) Tried to apply "Staff Engineer" formula to eng strategy topic, with a lot more editing 😂
www.amazon.com/Crafting-Eng...
www.amazon.com/Crafting-Eng...
Reposted by Pierre Zemb
At long last, @chris.blue and I have submitted the final manuscript of Designing Data-Intensive Applications, second edition, to the publisher. There is always more that could be improved but at some point we just have to call it done. Now it goes into production; probably shipping in ~4 months.
October 20, 2025 at 7:54 PM
At long last, @chris.blue and I have submitted the final manuscript of Designing Data-Intensive Applications, second edition, to the publisher. There is always more that could be improved but at some point we just have to call it done. Now it goes into production; probably shipping in ~4 months.
Flink Watermarks…WTF? flink-watermarks.wtf
Flink Watermarks…WTF?
Master Apache Flink watermarks with this interactive simulation. Learn what they are, why you need them, and how to configure them through hands-on examples.
flink-watermarks.wtf
October 20, 2025 at 1:23 PM
Flink Watermarks…WTF? flink-watermarks.wtf
pqr.sql: Generate QR Codes with Pure SQL in #PostgreSQL - Tanel Poder Consulting tanelpoder.com/posts/genera...
pqr.sql: Generate QR Codes with Pure SQL in PostgreSQL - Tanel Poder Consulting
As my cat woke me up way too early for a Saturday morning, I decided to put all this extra time (and my ChatGPT Pro subscription) into good use and generated a QR-code generator for PostgreSQL,…
tanelpoder.com
October 13, 2025 at 7:00 AM
pqr.sql: Generate QR Codes with Pure SQL in #PostgreSQL - Tanel Poder Consulting tanelpoder.com/posts/genera...
One Year of Hacking Workshops rhaas.blogspot.com/2025/07/one-...
One Year of Hacking Workshops
I started running PostgreSQL Hacking Workshops just about one year ago, and I've run one each month, except for May, when we had pgconf.dev....
rhaas.blogspot.com
October 6, 2025 at 6:38 AM
One Year of Hacking Workshops rhaas.blogspot.com/2025/07/one-...
Modernizing GNOME www.youtube.com/watch?v=uCAl...
Modernizing GNOME
https://media.ccc.de/v/all-systems-go-2025-364-modernizing-gnome
GNOME has collected some very old code over the years. During the recent GNOME 49 release, we've made some drastic cleanups. Most…
www.youtube.com
October 6, 2025 at 6:37 AM
Modernizing GNOME www.youtube.com/watch?v=uCAl...
Quick blogpost about a nice trick I discovered yesterday in #rustlang: that Deref bound I already had? Turns out it's all you need for universal Arc/Box/T APIs. Sometimes the solution is right there!
pierrezemb.fr/posts/from-a...
pierrezemb.fr/posts/from-a...
From Arc to Box: One Deref Bound to Rule Them All
How Rust's Deref trait solved a complex API design problem in FoundationDB-rs without traits or enums
pierrezemb.fr
October 2, 2025 at 12:00 PM
Quick blogpost about a nice trick I discovered yesterday in #rustlang: that Deref bound I already had? Turns out it's all you need for universal Arc/Box/T APIs. Sometimes the solution is right there!
pierrezemb.fr/posts/from-a...
pierrezemb.fr/posts/from-a...