David Crawshaw

David Crawshaw

@crawshaw.io

ceo exe.dev, tailscale co-founder, programmer

3.8K followers232 following627 posts

David Crawshaw reposted

Josh Bleecher Snyder
@commaok.xyz

Replying to @filippo.abyssdomain.expert

Dependency-less Python has been our default "scripting language" for a while at exe. Zero regrets, even before uv or ty. h/t @philz.dev

David Crawshaw
@crawshaw.io

Truly amazed how useful GLM is for anything network/ops/security. It is clearly behind the frontier models in sophistication, but By George it has gumption. A willingness to try goes far.

David Crawshaw reposted

Russ Cox
@swtch.com

The details are now public, as of two hours ago. bugzilla.mozilla.org/show_bug.cgi... The secret P-384 keys for these intermediate CAs are all zeros except the last 8 bits. All not-updated software can be MITM'ed now. IOT boxes that can't or don't update are now trivially MITM'able forever.

bugzilla.mozilla.org2083449 - Private key compromise of eMudhra Intermediate CertificatesNEW (nobody) in CA Program - CA Certificate Compliance. Last updated 2026-10-20.
Russ Cox@swtch.com

If you make HTTPS requests or have other TLS clients and care about MITM attacks, you need to update today. If you run Go: go get go@1.27.3 If you run Homebrew: brew update brew install ca-certificates If you run Linux, maybe stay off the internet for now.

David Crawshaw
@crawshaw.io

So CA’s proposition system is not great. But this election cycle I learned a new and astonishing fact: the proposition text you are voting for is not the law being passed. Each proposition can have multiple pages of legal text that is enacted.

David Crawshaw
@crawshaw.io

If you happen to vote in CA, and are leaning towards voting for a proposition, please look up the actual law you are voting to enact. There are surprising details!

David Crawshaw
@crawshaw.io

This is well-known to those who have been running VMs for a while but is not easily learned if you're new to the space, so we figured it should have a blog post. We have also exposed control over kernel scheduling cookies in a way we believe is novel.

exe@exe.dev

Sharing a CPU core comes with a security tradeoff. At exe, your team’s VMs can share cores with each other. Other teams’ VMs stay separate. And if your own VMs need that separation too, your team admin can turn sharing off. Ian explains how it works: blog.exe.dev/crossing-the...

blog.exe.devCrossing the Hyper-Thread Boundary - exe.dev blogYour VMs can share a CPU core. You get to decide who they share it with.
David Crawshaw
@crawshaw.io

Very happy to see the IceCube telescope win the Nobel. Probably the most cost/time effective physics instrument of my life, and the perfect hack.

David Crawshaw reposted

bitdrift
@bitdrift.io

🎙️ It's our favorite time of week, it's new episode release day! Hear how @crawshaw.io started Tailscale, why he made his way to the US, what he's up to now as CEO of exe.dev, plus the unexpected result of a recent HP printer purchase 😱 Full episode here: bitdrift.io/podcast/beyo...

bitdrift.iobeyond the noise - David Crawshaw: From Tailscale to exe.dev, and Why AI Agents Need Their Own ComputersDavid Crawshaw joins Matt Klein to discuss founding Tailscale, building exe.dev, and why AI agents need real computers.
David Crawshaw
@crawshaw.io

The hardest part of developing little programs for yourself right now is setting up an environment to run them. This is the idea of @exe.dev, open the app on your phone, start typing, you have a program on a durable Linux sandbox.

Philip Z@philz.dev

Four quick prompts to make a custom feed bsky.app/profile/did:... for myself on an @exe.dev VM.

David Crawshaw reposted

Vishnu Gopal
@vishnugopal.com

Trying out @exe.dev and it's so cool! Built a website for my wife in about 10 minutes. Easy for her to edit too since it's wired up to ChatGPT. You just ask it to make changes and it does. There's also something magical about executing commands like this: `ssh exe.dev share set-public <vm-name>`

David Crawshaw reposted

Filippo Valsorda
@filippo.abyssdomain.expert

Setting up Gerrit on @exe.dev with X-ExeDev-Email auth took 60s! However, that doesn't make git work. I hacked together a little proxy that does a tiny amount of OAuth2, exchanging exe.dev auth in the browser for a token that works with git-credential-oauth.

github.comGitHub - filippo-claude/gerrit-exedev-auth-proxy: Authenticate Gerrit web and Git smart HTTP with exe.dev OAuthAuthenticate Gerrit web and Git smart HTTP with exe.dev OAuth - filippo-claude/gerrit-exedev-auth-proxy

David Crawshaw reposted

exe
@exe.dev

We're going to be sharing more about how people use exe to build cool stuff. First up—a conservationist who turned 40 terabytes of public data into a video game: blog.exe.dev/meet-the-con...

blog.exe.devMeet the Conservationist Who Turned 40 Terabytes of Public Data Into a Video Game - exe.dev blogRaffael Hickisch spent years dreaming up conservation tools he couldn't afford to build. Then he built them himself, with an AI agent and a country's worth of public data.
David Crawshaw
@crawshaw.io

All these "clientless" compute options appearing over SSH. Someone tried to sell me one today in an HN comment thread. Truly, the sincerest form of flattery.

David Crawshaw
@crawshaw.io

I am convinced that commercial LLM offerings are bad at writing as a side effect of their post-training. I saw better writing from open base models 18 months ago. I cannot even trust a "frontier" model to write dev docs. More evidence we need a future of many models.

David Crawshaw
@crawshaw.io

nyc fighting waymo is like reading about people who used to fight seatbelts. every time I see young children cross at the intersection near my house where a pedestrian was killed earlier this year, I wish autonomous vehicles were in my neighborhood.

David Crawshaw
@crawshaw.io

one of the amazing things about autonomous vehicles is how they make human drivers around them better drivers. you see a waymo in sf actually stop at the stop sign, which means the human behind them rolls the stop sign at a slower speed.

David Crawshaw
@crawshaw.io

This is a limit of large human institutions. A large group cannot trust its own people, because large groups include bad people. So you have to build in checks and enforce them. But some people cannot operate effectively under those constraints. So some of the best people stick to small teams.

David Crawshaw
@crawshaw.io

Exactly how effective you can be depends on many factors. E.g. I was effective by large company standards when I worked there, by their measures. You get more resources and more constraints. But I am net more effective in smaller, high-trust organizations, so I suspect I will stick to them.

David Crawshaw
@crawshaw.io

To get good value out of agents you need a good development cycle. For an iOS app that means: while you are playing with the app, see a bug, you flip over to the agent, explain the problem, and then your app is updated with the fix. It's a REPL for iOS dev. Takes a lot of setup.

Philip Z@philz.dev

Behind the scenes on how the exe.dev iOS app was built: blog.exe.dev/ios-developm.... Step 1: buy mac mini. Step 2: give Shelley access to simulator. Step 3: over the air updates, Step 4: prompt app into existence from itself. Also, gratuitous profiler. boldsoftware.github.io/public_html/...

exe.devexe.dev - ssh exe.devBuild apps or SSH into a persistent Linux VM. ssh exe.dev.

David Crawshaw reposted

Philip Z
@philz.dev

Me, reaping: *startled* *fart noises emanating from Mac* TEN MIN PRIOR Me, sowing: "Shelley, build an iPad sound machine; test with the simulator." THIRTY MIN PRIOR "I learned how to build iPad apps at work; kids, what shall we make?" TODAY exe.dev has an iOS app blog.exe.dev/ios

David Crawshaw
@crawshaw.io

It makes me really happy to think of all the people who went into aerospace, not because they saw it as a path to wealth but as a way to do something that needed doing, also ending up with a financial windfall. They deserve the win.