Pierre Zemb
@pierrezemb.fr
🧑💻 Staff Engineer @clever-cloud.com 🤩 Distributed and Database Systems 🚀 Co-leader Finistdevs.org 💪 Squash player
#ApacheAvro frustrates a lot of people: you need two schemas just to decode a record. That annoyance is exactly why I like it. Here's why schema resolution makes rolling upgrades boring, in a good way. pierrezemb.fr/posts/why-ap...
Why Apache Avro Needs Two Schemas
Avro payloads cannot be decoded without the writer schema, and that two-schema model is what makes rolling upgrades and schema evolution work.
pierrezemb.fr
Engineering management after the cost of code collapsed: “Investing in machine-checkable correctness is now among the highest-leverage infrastructure work an org can fund” karimjedda.com/engineering-...
☀ "Et si on faisait du simulation-driven development ?" par @pierrezemb.fr Découvrez le Deterministic Simulation Testing (DST) pour simuler et diagnostiquer les scénarios et pannes de systèmes complexes de manière totalement déterministe. #SunnyTech
📍 @sunnytech.bsky.social — 02 & 03/07, Montpellier Retrouvez Julia Buchner, Pierre Zemb, @LostInBrittany, Alexandre Burgoni et Aurélien Hébert sur notre stand. @pierrezemb.fr y donnera aussi sa conférence : « Et si on faisait du simulation-driven development ? ». sunny-tech.io
Sunny Tech
Sunny Tech est la 1ère conférence Tech organisée à Montpellier. Une conférence annuelle des technologies du numérique, créée par des passionnés, pour des passionnés avec l’ambition de rayonner nationa...
sunny-tech.io
Honored to be featured by @eatonphil.bsky.social in The Consensus 🙏 We talked about the data services we are building at @clever.cloud, all API-compatible with Redis, PostgreSQL and etcd on top of FoundationDB. Give it a read 👇
Phil Eaton@eatonphil.bsky.social · 2mo agoI spoke with Pierre Zemb from French neo-compute company Clever Cloud. They're building data services API-compatible with popular systems like Redis, PostgreSQL, and etcd on top of FoundationDB and Pierre is leading the work. There is no paywall, give it a read. theconsensus.dev/p/2026/06/18...
I spoke with Pierre Zemb from French neo-compute company Clever Cloud. They're building data services API-compatible with popular systems like Redis, PostgreSQL, and etcd on top of FoundationDB and Pierre is leading the work. There is no paywall, give it a read. theconsensus.dev/p/2026/06/18...
Me, denied by FoundationDB's simulation because my PoC wasn't reboot-proof 🤯
I just published 'Designing Fakes That Prove Correctness' ✍️ The blog also has a new theme, and it hides a quorum easter-egg: flip to single-replica reads and see what it was protecting you from 👀 pierrezemb.fr/posts/design...
Designing Fakes That Prove Correctness
You fake the handful of methods your code actually calls, prove the fake stays honest, and then make it fail the way production does.
pierrezemb.fr
[𝗖𝗞𝗘] Quand @zwindler.fr attend notre Kubernetes managé depuis des années, puis ouvre le capot dès la bêta publique, forcément on lit attentivement 👀 Merci Denis pour ce retour et vivement la partie 2 !
Denis@zwindler.fr · 3mo agoJ'attends le #Kubernetes managé de @clever.cloud depuis des années. J'avais même déployé un CP K8s sur leurs "apps Linux" juste pour patienter 😅 CKE (Clever Kubernetes Engine) est enfin en bêta publique. Un premier post pour en parler (il y en aura d'autres) blog.zwindler.fr/2026/05/12/t...
La session de mai du FinistDevs, c’est mardi 12 mai à 18h30 chez Zenika Brest. Au programme • Xavier Rollet: “Un environnement de dev sur mesure avec NixOS” • Benoît Morin / Ifremer: “Centre Datarmor”, HPC, IA, big data et infrastructures scientifiques Inscription : www.meetup.com/finistdevs/e...
Soirée FinistDevs Mai 2026, Tue, May 12, 2026, 6:30 PM | Meetup
Salut à toutes et à tous, La session de mai du FinistDevs aura lieu le **mardi 12 mai à 18h30**, toujours chez **Zenika Brest**. Au programme : deux talks, avec du Linux
meetup.com
I gave a lightning talk at #BugBash 2026, sharing the stage with people whose work shaped how I think about distributed systems. Still processing that. Wrote up why the correctness decade has started, and why you trust the simulator, not Claude 👀 pierrezemb.fr/posts/bugbas...
BugBash 2026, or how the correctness decade has started
A retrospective on BugBash 2026, and why software engineering looks brighter than ever.
pierrezemb.fr
Et hop, je mets la touche finale à mes slides alors que le train arrive à Montparnasse. C'est bon, je suis prêt pour @devoxx.fr demain matin ! Si vous voulez savoir comment marche un moteur de requête, c'est demain à 10h30 ! m.devoxx.com/events/devox...
Devoxx Mobile Companion
Your ultimate companion for Devoxx conferences worldwide. Browse talks, speakers, schedules, and manage your personalized conference experience.
m.devoxx.com
On my way to #BugBash 2026 🤩 First Paris, then Washington DC ✈️ I will be presenting a lightning talk about how we borrowed #foundationdb simulation framework in #rustlang
DataFusion 53 came out last week. I took a look at the individuals and companies who committed the most. (paywall has expired) theconsensus.dev/p/2026/04/03...
How #NASA Built #Artemis II’s Fault-Tolerant Computer – Communications of the ACM cacm.acm.org/news/how-nas...
How NASA Built Artemis II’s Fault-Tolerant Computer – Communications of the ACM
Membership in ACM includes a subscription to Communications of the ACM (CACM), the computing industry's most trusted source for staying connected to the world of advanced computing.
cacm.acm.org
I just published a post on why I think fakes are more powerful than both mocks and Testcontainers. A fake that is worse than production: dropping writes, returning stale data... It catches the bugs that containers faithfully hide. pierrezemb.fr/posts/why-fa...
Why Fakes Beat Mocks and Testcontainers
Trait-based fakes test partial failures that mocks and Testcontainers fundamentally cannot simulate. They are also the on-ramp to simulation-driven development.
pierrezemb.fr
I just gave a talk "Testing: prevention vs discovery" at the #FinistAI x #FinistDevs crossover meetup 🧪 DST is the ultimate feedback loop for LLMs. It lets them discover what they don't know. No recording, but slides are available: pierrezemb.fr/slides/2026-... #deterministic #simulation #LLMs
👀 How does a #fuzzer find a 3-byte crash sequence in 9,000 iterations instead of 16 million? 🛠 Coverage turns a multiplicative problem into an additive one. I built a minimal #rustlang fuzzer from scratch to understand how it works: pierrezemb.fr/posts/diving...
Diving Into Coverage-Guided Fuzzing
How a 600-line Rust fuzzer discovers a 3-byte crash sequence in 9,000 iterations instead of 16 million
pierrezemb.fr
Rob Pike's 5 Rules of Programming "write stupid code that uses smart objects" is my favorite one! www.cs.unc.edu/~stotts/COMP...
Rob Pike's 5 Rules of Programming
Pike's rules 1 and 2 restate Tony Hoare's famous maxim "Premature optimization is the root of all evil."
cs.unc.edu
Google Engineers Launch "Sashiko" For Agentic AI Code Review Of The Linux Kernel - Phoronix www.phoronix.com/news/Sashiko...
Google Engineers Launch "Sashiko" For Agentic AI Code Review Of The Linux Kernel
Google engineers have been spending the past number of months developing Sashiko as an agentic AI code review system for the Linux kernel
phoronix.com
"Even in healthy clusters, MariaDB Galera Cluster exhibited Lost Update and Stale Read" Jepsen: MariaDB Galera Cluster 12.1.2 jepsen.io/analyses/mar...
Jepsen: MariaDB Galera Cluster 12.1.2
MariaDB Galera Cluster is a replicated version of MariaDB, a popular SQL database. While MariaDB claims Galera ensures “no lost transactions”, it loses transactions in at least two scenarios. First,…
jepsen.io
📝 The datafusion-index-provider PoC from last year is now a real library in datafusion-contrib, running in production. 🔧 New post on building secondary index queries with standard DataFusion operators pierrezemb.fr/posts/datafu... #Rust #DataFusion
Building Index-Backed Query Plans in DataFusion
What I learned about manually constructing physical query plans for secondary index queries, and the library that came out of it.
pierrezemb.fr
The second edition of Designing Data-Intensive Applications, by myself and @chris.blue, is finished and sent off to the printers! Ebooks should be available in the next week, and print books in 3–4 weeks. Sigh of relief. 😅 (BTW, this is a good opportunity to support your favourite local bookshop!)
👀 Turns out I'm #163 on the most active GitHub committers list in France A non-trivial amount of credit goes to #ClaudeCode, my favorite coding partner these days! committers.top/france
committers.top - Most active GitHub users in France
A list of most active GitHub users in France.
committers.top
✍️ I just published "Simulating Leader Election on top of FoundationDB" 🧪 Can LLM-generated code be trusted for distributed systems? Only if you have the right feedback loop. pierrezemb.fr/posts/simula... #FoundationDB #rustlang #simulation
Simulating Leader Election on top of FoundationDB
Can LLM-generated code be trusted for distributed systems? Only if you have the right feedback loop.
pierrezemb.fr
💡 In #FoundationDB, your reads determine whether YOU conflict. Your writes determine what OTHERS conflict with. ✍️ Wrote about OCC patterns for layer engineers: phantom conflicts, snapshot reads, atomic ops, and versionstamps. pierrezemb.fr/posts/fdb-tr...
FoundationDB's Transaction Model for Layer Engineers
How optimistic concurrency control works in FoundationDB, and how to design data structures that stop fighting it
pierrezemb.fr
