New from Fly.io today: Sprites.dev . Here's their blog post and YouTube demo . It's an interesting new product that's quite difficult to explain - Fly call it "Stateful sandbox environments with checkpoint & restore" but I see it as hitting two of my current favorite problems: a safe development environment for running coding agents and an API for running untrusted code in a secure sandbox. Disclosure: Fly sponsor some of my work. They did not ask me to write about Sprites and I didn't g...

Introduction Donald Knuth wrote his 1989 paper “A Simple Program Whose Proof Isn’t” as part of a tribute to Edsger Dijkstra on the occasion of Dijkstra’s 60th birthday. Today’s post is a reply to Knuth’s paper on the occasion of Knuth’s 88th birthday. In his paper, Knuth posed the problem of converting 16-bit fixed-point binary fractions to decimal fractions, aiming for the shortest decimal that converts back to the original 16-bit binary fraction. Knuth gives a program nam...

I found some vulnerabilities in Cashu's protocol for deterministic wallet recovery. I found some vulnerabilities in Cashu's protocol for deterministic wallet recovery.

My favorite albums from last year. Balkan brass, an acoustic favorite of 80s returns, Ethio-jazz, Guatemalan singer-guitarist, jazz-rock/Indian classical fusion, and a unique male vocalist. more… My favorite albums from last year. Balkan brass, an acoustic favorite of 80s returns, Ethio-jazz, Guatemalan singer-guitarist, jazz-rock/Indian classical fusion, and a unique male vocalist. more… My favorite albums from last year. Balkan brass, an acoustic ...

This week on the People and Blogs series we have an interview with Bix Frankonis, whose blog can be found at bix.blog . Tired of RSS? Read this in your browser or sign up for the newsletter . The People and Blogs series is supported by William Jansson and the other 129 members of my "One a Month" club. If you enjoy P&B, consider becoming one for as little as 1 dollar a month. Let's start from the basics: can you introduce yourself? My...

I didn't know what to put as a header so here are some iClouds (interesting clouds) in Maine I’ve had a lot of fun working with CKSyncEngine over the last month or so. I truly think it’s one of the best APIs Apple has built, and they’ve managed to take a very complex topic (cloud syncing) and make it very digestible and easy to integrate, without having to get into the weeds of CKOperation and whatnot like you had to in previous years. That being said, there’s a fair bit of wo...

Using a virtual environment is a well-known and important best practice for working on Python projects that use third-party dependencies, i.e. pretty much every Python project out there. But it’s a hassle to make sure you always have the right one activated, that you have one activated, and checking if there’s even one present. Maybe you haven’t created one for this project yet, yet where you’ve checked it out from source control. This post shares a simple shell script that will auto...

This document curates the most common questions Shreya and I received while teaching 700+ engineers & PMs AI Evals. Warning: These are sharp opinions about what works in most cases. They are not universal truths. Use your judgment. 👉 Want to learn more about AI Evals? Check out our AI Evals course . It’s a live cohort with hands on exercises and office hours. Here is a 25% discount code for readers. 👈 Listen to the audio version of this FAQ If you prefer to listen ...

Hey. It's been a while. I've been meaning to reach out, but work and the kids -- you know how it goes. I think about you surpringly often. Yesterday I saw a lone coconut at the grocery store and I literally guffawed . After all these years, I still don't know how to open a stupid coconut. I hope coconuts still baffle you too. I miss being idiots together. The truth is, I've been avoiding you. I miss you, but I'm afraid that you've changed as much as I have. I don't want to admit that mayb...

For the past decade, I've used Mailhog for local email debugging. Besides working on web applications that deal with email, I've long used email as the primary notification system for comments on the blog. I built an Ansible role for Mailhog , and it was one of the main features of Drupal VM , a popular local development environment for Drupal I sunset 3 years ago. Unfortunately, barring any future updates from the maintainers, it seems like Mailhog has not been maintained for four yea...

I put the tutorial on discrete event simulation on hold a couple of days ago and spent a few hours building a small discrete event simulation framework of my own using async / await instead of yield . As I hoped, I learned a few things along the way. First, Python’s await is just a layer on top of its iterator machinery (for an admittedly large value of “just”). When Python encounters await obj it does something like this: iterator = obj . __await__ () # get an iterat...

Global view of Mars from the Mangalyaan spacecraft, captured on October 4, 2014. Image: ISRO / Emily Lakdawalla Reviewing Mangalyaan, India’s first Mars mission India’s Mars orbiter completes six years at the red planet, but where is the science? Debate: Mangalyaan’s low science output still reflects on ISRO Mangalyaan spacecraft terminated—it was never a science mission My article on Mangalyaan was rejected 8 times but I published it anyway Views of Mars from India's Mangalyaan orbiter...

I'm posting from Oxford University where I will be spending the "Hilary Term" (through late March) as a visiting fellow at Magdalen College. If you are relatively local, reach out if you'd like to connect. I plan to get back into research after thirteen years of administration, working primarily with Rahul Santhanam and his group. I haven't had a significant sabbatical or leave since Amsterdam 30 years ago, which is what comes from changing jobs too often. Today I'd like to talk about a 2006 pap...

Programming note: Happy New Year! Bits about Money is made possible—and freely accessible to all—by the generous support of professionals who find it useful. If you’re one of them, thank you—and consider purchasing a membership . The U.S. is often maligned as being customer-hostile compared to other comparable nations, particularly those in Europe. One striking counterexample is that the government, by regulation, outsources to the financial industry an effective, virtually comprehen...

Hello! This past fall, I decided to take some time to work on Git’s documentation. I’ve been thinking about working on open source docs for a long time – usually if I think the documentation for something could be improved, I’ll write a blog post or a zine or something. But this time I wondered: could I instead make a few improvements to the official documentation? So Marie and I made a few changes to the Git documentation! a data model for Git After a while working on the docume...

When the balloon goes up in time of war, history has shown strategically important fixed targets take a beating. Just ask the Iraqi Air Force about January 17, 1991, the Pakistani Air Force about May 7, 2025, or Admiral Kimmel about the morning of December 7, 1941. Breaking news! The enemy has the precise coordinates of every two-mile runway in the world, knows the location of a majority of our fuel farms, and possesses the stick to reach them. Carl von Clausewitz — a scary brilliant 18th-...

Nearly 200 years ago, the physicists Claude-Louis Navier and George Gabriel Stokes put the finishing touches on a set of equations that describe how fluids swirl. And for nearly 200 years, the Navier-Stokes equations have served as an unimpeachable theory of how fluids in the real world behave — from ocean currents threading their way between the continents to air wrapping around an aircraft’s… Source Nearly 200 years ago, the physicists Claude-Louis Navier and George Gabriel Stokes put...

Converting the performance of a stock between currencies naively does not capture currency effects, even though they play a secondary factor long-term. Converting the performance of a stock between currencies naively does not capture currency effects, even though they play a secondary factor long-term.

A summary of my personal tech stack as we start 2026. I previously did one of these in 2024 . I was prompted to write this one by David Bushell and Robb Knight ’s App Defaults 2026 posts. My desk in late 2025. Software My dotfiles are public so if you’re curious about the configuration of some of the tools mentioned below check out github.com/wezm/dotfiles . Operating System: Arch Linux on my desktop, Chimera Linux on m...

That sounds like a Crash Test Dummies song. Fun story, my sister went to their latest concert in Sydney, and got me an autographed copy of their Afternoons and Coffee Spoons LP! Amazing. Coffee cards are a fixture of Australian café culture. The general idea is that after you’ve purchased a certain number of caffeinated beverages, you can redeem a free one. Often this extends to other drinks like tea and hot chocolate too, depending on the shop. Expensive chains have magnetic cards, but t...

When I was younger, in my 20s, I assumed that everyone was working “hard,” meaning a solid 35 hours of work a week. Especially, say, university professors and professional engineers. I’d feel terribly guilty when I would be messing around, playing video games on a workday. Today I realize that most people become very adept at avoiding actual work. And the people you think are working really hard are often just very good at focusing on what is externally visible. They show up to the right...

0.0 Context Setting Wednesday, 7 January 2026 in Portland, Oregon where it is wet (but not too wet) and cold (but not too cold), merely a typical brisk dreary day that recalls the less tumultuous and blissfully ignorant late 2009s/early 2010s. I accidentally words this time -- started writing them yesterday as long-form versions of things that caught my attention and were shat out onto Bluesky. 0.1 Events Hallway Track I am rearranging my schedule and hope to bring Hallway Track back ...

The End of The Orbital Index Issue No. 350  | Jan 7, 2026 🚀 🌎 ✌️   ...