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John Feminella

@jxf.me
143 followers 57 following 549 posts

🥰: bits, bots, bucks, blocks ⏪: Two Sigma, EY, HHCS, Thoughtworks, Pivotal, Forge. 👤: Thing builder, conf speaker, curiosity advocate, dad.

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John Feminella @jxf.me · 13h
I posted about speaking at a conference on LinkedIn and got 162 (!) recruiter messages in the course of 24 hours. Insanity; how do people deal with this spam?
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John Feminella @jxf.me · 29/09/2026
I can think of several smart humans who might be interested in trying this out, but my general take is that if you ever liked HyperCard you'll like Scrubjay:
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John Feminella @jxf.me · 29/09/2026
After a few weeks of occasionally clicking this button on LinkedIn, I can report that my feed is materially less horrible.
A screenshot from LinkedIn's message options. One labeled "Seems like AI slop" is highlighted.
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John Feminella @jxf.me · 27/09/2026
People who can't reason about (or won't consider) the impact of systems in their lives are doomed to blame individuals for their problems.
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John Feminella @jxf.me · 25/09/2026
The trick is to create the box such that you don't care if Claude runs "rm -rf /". 😄
A satirical meme riffing on the "Frog and Toad" children's book series. Frog is holding a box and talking to Toad. The text below says:

Frog put Claude in a box. "There," he said. "Now he cannot run rm -rf /." "But he can run bash -c 'rm -rf /', said Toad. "That is true," said Frog.
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John Feminella @jxf.me · 25/09/2026
#rust folks: this is your periodic reminder to `cargo clean`
"Removed 87414 files, 50.9GiB total" reported by `cargo clean`.
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John Feminella @jxf.me · 23/09/2026
By far the funniest thing I've ever read. Honey manufacturing is Gravitron for bees!
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John Feminella @jxf.me · 21/09/2026
Sucked into a hell vortex of flight diversions and cancellations right at the start of my day. Someday the country where the Wright Brothers launched a plane will figure out how to have operational airports. newjersey.news12.com/2026/09/21/f...
newjersey.news12.com
FAA issues ground stop at Newark airport due to equipment outage
Flights headed to Newark were grounded Monday morning, while departures from the airport were experiencing increasing delays.
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John Feminella @jxf.me · 21/09/2026
"Has that ever panned out?", he said, posting his thoughts into an electronic ether instead of painstakingly arranging cast-iron pieces of movable type into a printing press, pulping wood himself to make paper, and nailing his ideas to a tree in the town square.
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John Feminella @jxf.me · 19/09/2026
Get 10 million Amex points with this one weird trick: paying $100,000 for a room during UN General Assembly week in NYC.
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John Feminella @jxf.me · 18/09/2026
0% chance this goes well. The reason there's congestion is not because we don't have enough AI, it's because we don't have enough controllers. arstechnica.com/ai/2026/09/f...
arstechnica.com
FAA tees up $875M AI tool to help manage air traffic congestion
FAA plans for AI tool to help manage DC air traffic before a nationwide rollout.
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John Feminella @jxf.me · 18/09/2026
Cannot believe I've been a US citizen for four decades and only just noticed that "Kansas" is a substring of "Arkansas", but they're pronounced completely differently. 🤯
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John Feminella @jxf.me · 17/09/2026
Spotted this very handsome great-tailed grackle delightedly enjoying a bath outside my hotel.
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John Feminella @jxf.me · 16/09/2026
Famously, Jesus also tried turning it off and then on again, but it took 72 hours to reboot.
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John Feminella @jxf.me · 16/09/2026
Actual quote from an Anthropic architecture doc explaining their new function hooks: "A hook is Koa-style middleware: it reifies an endomorphic continuation."
"A hook is Koa-style middleware: it reifies an endomorphic continuation."
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John Feminella @jxf.me · 14/09/2026
I'm almost certainly in a bubble with `jj`, the distributed version control system that's also Git-compatible. But it's a very nice bubble. I wouldn't be overly surprised if, in five years, enterprises are starting to try it out.
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John Feminella @jxf.me · 12/09/2026
Had to dredge up my chemistry knowledge to explain to the kids that this toy is not "salt water powered", but rather uses up a much more limited resource, magnesium: 2Mg + O₂ + 2H₂O → 2Mg(OH)₂ Notice the salt water (NaCl in H₂O) doesn't appear anywhere in the reaction!
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John Feminella @jxf.me · 11/09/2026
The problem with Amp orbs (ampcode.com), Pi (pi.dev), and all of the interesting "bake your own agentic environment/runtime" stuff is it's impossible to talk about it without sounding unhinged. The level of weird and unnecessary jargon is bizarre and makes me suspicious.
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John Feminella @jxf.me · 09/09/2026
Increasingly tempted to add a mandatory "slop check" to everyone's CI pipelines to prevent slop PR messages, log strings, comments, and other text from slipping through (or reduce them, at least).
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John Feminella @jxf.me · 09/09/2026
Nailed directly in the soul by opusfived.dev. Opus do just one thing challenge level: impossible. (This is why good harnesses are everything!)
opusfived.dev
Opusfived
Make one button blue. Change nothing else. A short interactive comedy about agentic AI assistants that can never just do the thing.
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John Feminella @jxf.me · 06/09/2026
Our cats watching me make dinner over a hot stove instead of simply going into the woods and hunting a field mouse.
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John Feminella @jxf.me · 06/09/2026
Hiked 8 miles this morning with some friends along the very peaceful and lovely Robinson River. It is now time for lunch: BLTs with greenhouse tomatoes from the garden.
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John Feminella @jxf.me · 01/09/2026
My "our website is completely legal" sign has people asking a lot of questions that are answered by the sign.
An ad for Kalshi reading "Kalshi Rule #4: We operate under U.S. law" with smaller text beneath reading "because Kalshi is a federally regulated U.S. exchange".
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John Feminella @jxf.me · 30/08/2026
If a character in a movie explains their plans in detail, the plan is guaranteed to go awry or fail completely. If they say "I've got a plan" but don't elaborate further, it goes off without a hitch. Any apparent derailing of the plan will turn out to be accounted for in the plan.
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John Feminella @jxf.me · 29/08/2026
"We've got his hard drives." Sir... that is a PC power supply unit.
A screenshot of Limitless S1E4 with an FBI agent saying "We've got his hard drives".
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John Feminella @jxf.me · 26/08/2026
Happy 35th birthday Linux!
Linux announcement on August 25, 1991 from Linus Torvalds to the University of Helsinki, entitled "What would you like to see most in minix?"
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John Feminella @jxf.me · 25/08/2026
A note for code authors in this AI era: * PR has more than one goal? It's too complicated. * Can't understand the PR's goal? It's too complicated. * Can't understand how the commit achieved a step in the goal? It's too complicated. * Can't review a commit? it's too complicated.
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John Feminella @jxf.me · 23/08/2026
What I thought I was doing: calmly putting a single dusty, cracked 1×1 Lego that's been under the couch for six weeks into the recycling bin What my children perceived: Dad laughing evilly as he permanently destroys a vital and irreplaceable piece of their imaginarium, like some kind of MONSTER
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John Feminella @jxf.me · 21/08/2026
Tired mouse hunters after a long but exciting day of catching two (2) field mice in the backyard.
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John Feminella @jxf.me · 19/08/2026
Peak recession indicator
A banner from Charles Schwab reading "Schwab Crypto is coming soon" with Bitcoin and Ethereum logos.
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John Feminella @jxf.me · 13/08/2026
Anthropic removed a line in the system prompt that said "Default to no comments", so naturally Claude has now gone buckwild with comments. Teams love reviewing PRs like: ``` // let me sing you the song of my people: [5,000 more tokens] const TEASPOONS_PER_TABLESPOON: i32 = 3; ```
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John Feminella @jxf.me · 10/08/2026
Before, it was a bug. Now, it is a feature.
A wasp rolled over by a train, pressed into the rail of a train track.
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John Feminella @jxf.me · 09/08/2026
Beds are just shelves that I lay my bone armor mech suit onto when I'm not using it.
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John Feminella @jxf.me · 06/08/2026
Same energy.
static.klipy.com
Who's That Pokémon? Pikachu Reveal
Alt: The "Who's That Pokemon?" Pikachu reveal scene from the anime series "Pokemon".
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John Feminella @jxf.me · 28/07/2026
Hypothesis: The "it's not X, it's Y" pattern that LLMs are so fond of outputting can be traced back to a single, very prevalent phrase in the training data:
A screen capture of a commercial for DiGiorno Pizza, reading "It's not delivery... It's DiGiorno."
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John Feminella @jxf.me · 17/07/2026
Me looking at the air quality numbers on AQINow.
static.klipy.com
Chernobyl: Not Great, Not Terrible Quote
Alt: Clip from Chernobyl of Dyatlov saying "Not great, not terrible."
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John Feminella @jxf.me · 12/07/2026
My wife is out of town so the cat is settling for scratches from me tonight.
A very handsome cat gets scratches.
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John Feminella @jxf.me · 10/07/2026
This is going to turn out to be a single vibecoded Java class definition
A headline screenshot from TechRadar reading "Accenture confirms breach after hacker steals 35GB of source code and other data".
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John Feminella @jxf.me · 08/07/2026
If I were FTC Commissioner, I would mandate that all popups with a "Maybe later" button must also have a prominent "Never ask me again" button.
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John Feminella @jxf.me · 07/07/2026
Wish I could bottle up these 67°F July days in NYC to save for when it's 90°F in August.
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John Feminella @jxf.me · 01/07/2026
Stay cool! Find a cooling center near you: nchh.org/information-...
Screenshot of weather for Charlottesville, VA, showing highs of 104°F for Thursday, July 2.
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John Feminella @jxf.me · 24/06/2026
Incredible.
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John Feminella @jxf.me · 23/06/2026
Very curious to hear the detailed postmortem on Anthropic model failures this morning will be. Personally, I saw effects on the public Anthropic endpoints, but _also_ on Azure, AWS, and GCP, which is not typical outage behavior for model endpoints. Suggestive of a big configuration change, imo.
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John Feminella @jxf.me · 19/06/2026
Become ungovernable!
A black and white sign on a green wall, reading "REFUSE TO BE STORED IN BLACK PLASTIC SACKS AND PLACED IN THE CONTAINERS PROVIDED".
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John Feminella @jxf.me · 19/06/2026
Hot take: .gitignore should be for things _specific to that repository_. General files that should always be ignored go in your user-level .gitignore.
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John Feminella @jxf.me · 16/06/2026
In a very welcome move, it looks like @Anthropic is rolling back the `claude -p`/API SDK changes.
Email from Claude (Anthropic) addressed to John. The message reads: "In May, we sent you an email announcing that starting today, the Claude Agent SDK, claude -p, and third-party apps built on the Agent SDK would stop drawing from subscription rate limits and move to a dedicated monthly credit. We're writing to let you know that we're not making this change today. We're working to update the plan to better support how users build with Claude subscriptions." A section titled "What this means for you" reads: "Nothing changes for now. Agent SDK, claude -p, and third-party app usage continues to work with your subscription exactly as it did before today, and there's no credit to claim. Your subscription limits are unchanged. When we have an update, we'll share it with advance notice before it takes effect."

The footer includes the Claude logo, LinkedIn, X, and YouTube icons, and the address: Anthropic PBC, 548 Market St, PMB 90375, San Francisco, CA 94104.
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John Feminella @jxf.me · 08/06/2026
Controversial take: making your coding agent a coauthor on your commits is harmful in the long run. It invites too much abdication of responsibility.
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John Feminella @jxf.me · 08/06/2026
Idea: The Doomsday Clock (thebulletin.org/doomsday-clo...) but for the Butlerian Jihad.
thebulletin.org
Doomsday Clock - Bulletin of the Atomic Scientists
It is 85 seconds to midnight.
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John Feminella @jxf.me · 07/06/2026
✈️ Off to NYC. This week's trip and work is sponsored by the John T. and Catherine D. MacArthur Foundation, committed to building a more just, verdant, and peaceful world. (I've always wanted to say that!)
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John Feminella @jxf.me · 05/06/2026
If you love spending 6 hours in the RPG character creation screen instead of playing the game, Starship is for you (and me): starship.rs
starship.rs
Starship: Cross-Shell Prompt
Starship is the minimal, blazing fast, and extremely customizable prompt for any shell! Shows the information you need, while staying sleek and minimal. Quick installation available for Bash, Fish, ZS...
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