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Martin Kleppmann

@martin.kleppmann.com
34K followers 468 following 1.1K posts

Associate Professor at @cst.cam.ac.uk, researching decentralised systems and security protocols. Advisor to the Bluesky team. Wrote “Designing Data-Intensive Applications” (O’Reilly). he/him

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Martin Kleppmann @martin.kleppmann.com · 28/09/2026
Notion wrote a nice blog post on how they use CRDTs, including our Peritext algorithm for rich text! This must be one of the largest CRDT deployments out there? www.notion.com/en-gb/blog/h...
notion.com
How Notion handles concurrent editing with CRDTs
Building a CRDT-based rich-text system that merges concurrent edits across Notion blocks—without losing anyone’s work
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Martin Kleppmann @martin.kleppmann.com · 27/09/2026
Now even featured on TV! 😍 www.youtube.com/watch?v=Ktby...
youtube.com
Dinky Doors on ITV News Anglia
YouTube video by Dinky Doors
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Martin Kleppmann @martin.kleppmann.com · 25/09/2026
A researcher I'm working with in Cambridge, @zazbrown.com, just used AI and Lean to prove the Affine Plank Conjecture, an open problem for the last 75 years! (To be precise, he proved a special case not proven before; the general conjecture is still open.) zazbrown.com/research/pap...
zazbrown.com
The Affine Plank Conjecture | Zaz Brown
An illustrated explanation of relative plank widths, an interactive visualization, and proofs for three planks.
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Martin Kleppmann @martin.kleppmann.com · 25/09/2026
I only just found this post by @joehellerstein.bsky.social from February on how waiting, ordering, and commitment in distributed systems are all ways of looking at the same underlying idea: coordination. Good post, matches with how I think about it jhellerstein.github.io/blog/three-s...
jhellerstein.github.io
Three Lenses on Coordination
Three Sets of Specs (for Staying in Spec) In the last post I talked about how systems formalisms are like sculpting with a chisel: we remove behaviors we don’t…
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Martin Kleppmann @martin.kleppmann.com · 17/09/2026
There's a new Dinky Door in Cambridge! The cyclopunt – half cargo bike, half punt – best vehicle ever! www.dinkydoors.co.uk
A piece of miniature street art with the feet of people walking by out-of-focus in the foreground. The sculpture is a punt (a long flat boat) with the front and rear wheels of a cargo bike attached at both ends. The punt is loaded with parcels.The cyclopunt from a perspective where you can see a bit of the street scene as well. It's located in Rose Crescent in central Cambridge.
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Jake Gold @jacob.gold · 12/09/2026
There's no slowing down frontier models by regulation that wouldn't lead to regulatory capture. But we could simply force all AI model companies to release their model weights openly. It's the world's data after all and nothing would slow their funding/progress more effectively and universally.
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Automerge @automerge.org · 02/09/2026
🗞️ The August 2026 edition of This Month in Automerge is out! Check out what's new in the core libraries the last days of summer, and a few projects from the community that caught our eye 👀 automerge.org/blog/2026-au...
automerge.org
This Month in Automerge: August '26
Automerge 3.4.1, sturdier sync servers, a new access control guide, and news from around the ecosystem.
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Martin Kleppmann @martin.kleppmann.com · 02/09/2026
Interactive visualisation of the Raft consensus algorithm, linked with the pseudocode from my lectures — looks amazing!
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Martin Kleppmann @martin.kleppmann.com · 01/09/2026
Oh this looks amazing. Instant impulse purchase
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Ink & Switch @inkandswitch.com · 31/08/2026
Today we're officially sharing the "Introducing Patchwork-26" video from Lab Day at this year's @localfirstconf.com We bring you the first look at Patchwork-26, the latest in our ongoing effort to realize Malleable Software, Universal Version Control, and Local-First Software.
youtube.com
Introducing Patchwork-26
YouTube video by Ink & Switch
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Count Binface @countbinface.bsky.social · 11/08/2026
An American interviewer asked me about my political beliefs. #VoteBinface
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Automerge @automerge.org · 12/08/2026
📅👀 The next set of community calls are posted to the Luma. Excited to see everyone there (and we'll also have This Month in Automerge in between) Register here: luma.com/automerge
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Martin Kleppmann @martin.kleppmann.com · 12/08/2026
My fist as pinhole camera
Shadow of my raised fist against a wall. In the hole left between the fingers is the crescent of a partial (90%) solar eclipse
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Naomi Saphra @nsaphra.bsky.social · 09/08/2026
I've been unsettled lately when reading messages and papers. It feels like I'm dissociating. Everything seems a bit alien, even if it's completely human. I've had a realization: When our simulations finally exited the Uncanny Valley, they brought the Uncanny with them.
nsaphra.net
Life on the Uncanny Precipice | Naomi Saphra
We were wrong about the Uncanny Valley.
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Martin Kleppmann @martin.kleppmann.com · 09/08/2026
More details on the OpenAI/Hugging Face incident. Absolutely wild www.youtube.com/watch?v=87Dy...
youtube.com
Black Hat USA 2026: The 'Breaking' News: The OpenAI–Hugging Face Incident
YouTube video by Black Hat
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Brooklyn Zelenka @expede.wtf · 04/08/2026
Excited to have a ✨ guest post ✨ from @djwyen.bsky.social in our @inkandswitch.com Keyhive lab notes! The local-first setting is new to a lot of cryptographers; here Derek shares some of his insights working on the BeeKEM paper, cross-fork security (CFS), and fundamental protocol design tradeoffs 🐝
inkandswitch.com
06 · E2EE in the Local-First Setting
Examining design considerations for developing cryptography for the local-first setting.
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Martin Kleppmann @martin.kleppmann.com · 04/08/2026
An optimistic post on the role of human mathematicians (and scientists in general) in the age of AI www.noahpinion.blog/p/the-end-of...
noahpinion.blog
The end of the age of heroes
AI will soon be better at math than any human. What does that mean?
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Automerge @automerge.org · 31/07/2026
🆕 We're trying something new: here's the first ever This Month in Automerge 🗞️✨ Check out what's been happening in the core libraries, and a few projects in the ecosystem! automerge.org/blog/2026-ju...
automerge.org
This Month in Automerge: July '26
Hexane v1 lands in Automerge, Subduction sync server hardening, a BeeKEM paper preprint, and more.
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Martin Kleppmann @martin.kleppmann.com · 31/07/2026
My talk at @localfirstconf.com is up, in which I argue that local-first has a role to play in improving the resilience of democratic societies in an era of geopolitical tensions. I'm pretty happy with how this talk turned out www.youtube.com/watch?v=--Ru...
youtube.com
Martin Kleppmann — Local-first in an unstable world
YouTube video by Local-First Conf
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Martin Kleppmann @martin.kleppmann.com · 29/07/2026
lol thank you IEEE for giving me a good laugh (CC @mweidner.bsky.social)
BibTeX export of one of my papers from IEEE Xplore. The keywords field contains some plausible terms, but also some inexplicably odd ones, including "Dairy products"
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Simon Willison @simonwillison.net · 28/07/2026
Hugging Face just published a highly detailed technical account of OpenAI's accidental cyberattack on their systems - it's wild how sophisticated this was: huggingface.co/blog/agent-i... Wrote up some of my own notes here: simonwillison.net/2026/Jul/28/...
huggingface.co
Anatomy of a Frontier Lab Agent Intrusion: A Technical Timeline of the July 2026 Incident
We’re on a journey to advance and democratize artificial intelligence through open source and open science.
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Martin Kleppmann @martin.kleppmann.com · 26/07/2026
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-...
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Brooklyn Zelenka @expede.wtf · 22/07/2026
📃🐝✨ Excited to share a preprint about BeeKEM, a decentralized / local-first variant of MLS's TreeKEM (group E2EE) that we designed at @inkandswitch.com. Huge thanks to our coauthors for the writeup and empirical analysis — even we were pleasantly surprised by the performance results 📊
eprint.iacr.org
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dan @danabra.mov · 17/07/2026
ugh web is so complicated. that certificate authority looks quite centralized to me. and that CDN might end up expensive to run at scale. and do we really need another standard? just use email
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Martin Kleppmann @martin.kleppmann.com · 16/07/2026
What's your favourite solution for AI transcription / summarisation of video calls?
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Local-First Conf @localfirstconf.com · 13/07/2026
A few impressions from yesterday‘s talks 📸 @adamwiggins.com @martin.kleppmann.com @stevenruiz.bsky.social @jakelazaroff.com
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Martin Kleppmann @martin.kleppmann.com · 12/07/2026
So excited to be speaking at @localfirstconf.com in a few minutes!
Panorama photo of the stage and audience of Local First Conf
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pvh @pvh.ca · 04/07/2026
From research, to prototype, to a real plugin you can install in the Godot Asset Store, Backstitch is a branch of our research into universal version control brought to life in the Godot game engine! You can check it out now: store.godotengine.org/asset/inkand...
store.godotengine.org
Backstitch - Godot Asset Store
Real-time version control for Godot! Backstitch enables fast collaboration for dev teams, game jams, and classrooms.
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Coral City Camera @coralcitycamera.bsky.social · 03/07/2026
Our octo pal morphed its way through Coral City in broad daylight 👻🐙👽 #octopus #cephalopodsofcoralcity #colorchange #cephalopod #coralcitycamera
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Martin Kleppmann @martin.kleppmann.com · 02/07/2026
Jamie Brandon has a nice experience report on what's good and bad about current AI agents for writing code www.scattered-thoughts.net/writing/arti...
scattered-thoughts.net
Artificial adventures
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Martin Kleppmann @martin.kleppmann.com · 01/07/2026
Analysis of the physics and economics of datacenters in space spectrum.ieee.org/orbital-data...
spectrum.ieee.org
The Real Cost Of Cooling GPUs In Space Might Shock You
Shedding heat will require ingenious new designs
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Gretchen McCulloch @gretchenmcculloch.com · 27/06/2026
Someone suggested today at @labphon.bsky.social that academic posters need a QR code going to an email signup for "please send me the official version of this paper once it's done and citable" And all I could say was YES PLEASE CAN I HELP TWEET THIS INTO EXISTENCE
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Dr. Jonathan Foley @globalecoguy.bsky.social · 25/06/2026
I especially love this diagram.
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Anselm Eickhoff @anselm.io · 24/06/2026
TLDR
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Ivy Reese @spiralganglion.com · 21/06/2026
libraries are a technology they are a technological solution to a social problem when people say not to do that, they always mean "don't use a bad computer program to hurt people" — duh but i think the only good technologies are the ones that solve social problems www.bbc.com/future/artic...
bbc.com
Not just books - how renting a sewing machine from the library can improve democracy
Finland's libraries are increasingly being valued not by how many books they lend, but how they help societies function.
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Martin Kleppmann @martin.kleppmann.com · 20/06/2026
There's a special category of spam: dubious book promoters targeting authors. Mostly the emails are just lazy AI slop. But occasionally they are amusing, such as this one, praising the "character development, psychological depth" of a technical book that definitely has none of either of those 🤪
Screenshot of an email:

"Dear  Martin Kleppmann,

I hope this message finds you well.

My name is Johnson, and I am a Marketing Representative with USA TODAY Newspaper.

After carefully reviewing your work, we were impressed by the themes, character development, psychological depth, biography, encyclopedia value, and overall literary contribution presented in your book. Your work stood out to our editorial and marketing team, and we believe it would strongly connect with our readers and audience."
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Martin Kleppmann @martin.kleppmann.com · 19/06/2026
Backstitch (backstitch.dev) brings Automerge-based collaboration and version control to the Godot game engine. It's is vastly more usable than Git, and a lovely showcase of what Automerge can do. Great talk from Lilith Duncan introducing the project: www.youtube.com/watch?v=CAJ_...
youtube.com
Beyond Git: Real-Time Version Control for Godot – Lilith Duncan – GodotCon 2026
YouTube video by Godot Engine
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Hazel Weakly @hazelweakly.me · 18/06/2026
One of the secret reasons I’m bullish on local first is because the data structures and techniques involved are *also* the ones you would use to build highly resilient architectures that handle temporary total outages with graceful recovery. Exactly the properties needed for critical infrastructure
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Martin Kleppmann @martin.kleppmann.com · 18/06/2026
Local-First Conf @localfirstconf.com is now sold out, and the schedule looks excellent – lots of great people speaking! app-2026.localfirstconf.com/schedule
app-2026.localfirstconf.com
Schedule – Local-First Conf 2026
The world's first and best event dedicated to local-first software.
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Aaron Rodericks @aaron.bsky.team · 16/06/2026
The UK announcing the under 16 ban plays the right notes on 'safety' around a byelection. Do they know what's in the law? no idea! When will they write it? Possibly in 6 months, depends how many votes it's getting them. Is there evidence? People told us to do something! We are the party of safety!
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Iroh @iroh.computer · 15/06/2026
We just released the first stable version of iroh, v1.0! Read about it: www.iroh.computer/blog/v1 We're super proud of where we landed with iroh's 1.0. Since version 0.35 it feels like we've entirely replaced the "engine underneath". Are you a fellow key-dialer? Come tell us how you use iroh!
iroh.computer
Iroh 1.0 - Dial Keys, not IPs
Iroh 1.0 is out. Now is the time to build.
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Jared Forsyth @jaredforsyth.com · 09/06/2026
ok I think I've really got this working. - rich text CRDT (peritext-based) - movable blocks with split & join, retaining provenance and collaborative editing - strong cycle prevention both for split/join and block nesting annnd just for fun I've also implemented multicursor in the demo (cmd+click)
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Kiran @kirancodes.me · 13/06/2026
A short thread on my contributions to Computer Science www.youtube.com/watch?v=3Uw1...
youtube.com
Good Advice
YouTube video by Allan Sherman - Topic
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Martin Kleppmann @martin.kleppmann.com · 13/06/2026
The fact that the US government specifically ordered the suspension of Fable access to non-US citizens (www.anthropic.com/news/fable-m...) raises exactly the kind of technological sovereignty concerns I discussed in my QCon keynote a few months ago (www.infoq.com/presentation...)
anthropic.com
Statement on the US government directive to suspend access to Fable 5 and Mythos 5
The US government has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States.
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InfoQ @infoq.com · 11/06/2026
Europe's reliance on US cloud services is a geopolitical risk. ⚠️ How do we achieve #TechnologicalSovereignty? It starts with portability. @martin.kleppmann.com shares a roadmap to cloud independence using 2 tools: 1️⃣ Local-first software 2️⃣ The AT Protocol 🎬 Watch now: bit.ly/49UADtk #InfoQ20
bit.ly
Mitigating Geopolitical Risks with Local-First Software and atproto
Martin Kleppmann discusses the urgent need for technological sovereignty in modern infrastructure. Exploring the shifting landscape of global tech dependencies, he shares how engineering leaders can l...
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Martin Kleppmann @martin.kleppmann.com · 09/06/2026
Video and transcript from my talk at QCon London are now online. Thanks @qconferences.com! www.infoq.com/presentation...
infoq.com
Mitigating Geopolitical Risks with Local-First Software and atproto
Martin Kleppmann discusses the urgent need for technological sovereignty in modern infrastructure. Exploring the shifting landscape of global tech dependencies, he shares how engineering leaders can l...
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Lu wilson @todepond.com · 06/06/2026
new blog post: "The keynote business" www.todepond.com/sky/keynote/
todepond.com
Todepond dot com
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Martin Kleppmann @martin.kleppmann.com · 07/06/2026
Always nice to hear about apps using an algorithm we developed – in this case a tree CRDT with move operation (martin.kleppmann.com/papers/move-...). Thanks @avelino.run for the shout-out! outl.app/blog/outl-be...
outl.app
outl beta: three clients, one tree — outl blog
TUI, native desktop, and an iOS app on TestFlight — all reading the same workspace folder. Apple-first, same Rust core, zero cloud. Inside: how outl makes file sync converge using a tree-CRDT and an H...
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Ink & Switch @inkandswitch.com · 01/06/2026
Newsletter subscribers got Dispatch 017 last Thursday: A Peek at Patchwork Progress The next few months will be a blur in the run-up to @localfirstconf.com and the Lab Day we’re hosting as part of it. All our teams are busy prepping the work they’d like to show, polishing features, planning demos.
inkandswitch.com
A Peek At Patchwork Progress
It’s all hands on deck as we prepare Patchwork for the upcoming Local-First Conf in Berlin. Plus, Ivy Reese shares the technical & social design behind Tenfold.
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Gergő Bocsárdi @agbocsardi.com · 31/05/2026
Got inspired by this post! github.com/agbocsardi/a... Super experimental, but hey, it's a start!
github.com
GitHub - agbocsardi/academic-lsp: Experimental language server diagnostics for academic prose
Experimental language server diagnostics for academic prose - agbocsardi/academic-lsp
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