John Feminella
@jxf.me
🥰: bits, bots, bucks, blocks
⏪: Two Sigma, EY, HHCS, Thoughtworks, Pivotal, Forge.
👤: Thing builder, conf speaker, curiosity advocate, dad.
⏪: Two Sigma, EY, HHCS, Thoughtworks, Pivotal, Forge.
👤: Thing builder, conf speaker, curiosity advocate, dad.
How I'd describe our alliance infrastructure:
December 7, 2025 at 11:17 PM
How I'd describe our alliance infrastructure:
In this house, we obtain our facts only from America's finest news source.
December 4, 2025 at 10:13 PM
In this house, we obtain our facts only from America's finest news source.
When your job description includes "other duties as assigned".
November 26, 2025 at 5:35 PM
When your job description includes "other duties as assigned".
Happy Biweekly Cloud Outage Day to all who celebrate.
(This biweekly patron saint is Cloudflare.)
(This biweekly patron saint is Cloudflare.)
November 18, 2025 at 1:15 PM
Happy Biweekly Cloud Outage Day to all who celebrate.
(This biweekly patron saint is Cloudflare.)
(This biweekly patron saint is Cloudflare.)
Endlessly funny to me that the Swift shortcode for "payments initiation" is "pain". Very apt if you've ever tried to implement this yourself without reference to the standard!
November 16, 2025 at 4:53 PM
Endlessly funny to me that the Swift shortcode for "payments initiation" is "pain". Very apt if you've ever tried to implement this yourself without reference to the standard!
Devastating economic news.
November 6, 2025 at 9:22 PM
Devastating economic news.
Love to start Mondays with elevator malfunctions and 100 dB buzzer sounds.
October 27, 2025 at 2:34 PM
Love to start Mondays with elevator malfunctions and 100 dB buzzer sounds.
✈️ Good morning from Santa Monica.
October 23, 2025 at 3:07 PM
✈️ Good morning from Santa Monica.
OpenAI recently released Sora 2, their new video model. I had access to preview it this past week.
Just to give you a flavor of the general capabilities, here's a zero-shot 15-second video I made (no editing, no revisions). Prompt in thread.
Just to give you a flavor of the general capabilities, here's a zero-shot 15-second video I made (no editing, no revisions). Prompt in thread.
October 3, 2025 at 5:38 PM
OpenAI recently released Sora 2, their new video model. I had access to preview it this past week.
Just to give you a flavor of the general capabilities, here's a zero-shot 15-second video I made (no editing, no revisions). Prompt in thread.
Just to give you a flavor of the general capabilities, here's a zero-shot 15-second video I made (no editing, no revisions). Prompt in thread.
A totally normal, not at all unhinged banner to have on a nonpartisan government website.
September 30, 2025 at 4:09 PM
A totally normal, not at all unhinged banner to have on a nonpartisan government website.
Just discovered that even though Google Calendar's UI doesn't let you have multiple monthly recurrences (e.g. "first and third Tuesday of each month"), they can import and represent ICS files that do.
That means you can do something like this and it'll work correctly in Google Calendar:
That means you can do something like this and it'll work correctly in Google Calendar:
September 29, 2025 at 4:12 PM
Just discovered that even though Google Calendar's UI doesn't let you have multiple monthly recurrences (e.g. "first and third Tuesday of each month"), they can import and represent ICS files that do.
That means you can do something like this and it'll work correctly in Google Calendar:
That means you can do something like this and it'll work correctly in Google Calendar:
Example of a (real) interview, in this case with Howard Jacobson.
September 24, 2025 at 10:24 PM
Example of a (real) interview, in this case with Howard Jacobson.
It's immensely charming that Wikipedia still contains deeply technical articles that have, like, some rando's handwritten notes as the reference image for how an algorithm should work.
September 22, 2025 at 9:30 PM
It's immensely charming that Wikipedia still contains deeply technical articles that have, like, some rando's handwritten notes as the reference image for how an algorithm should work.
PSA: If you received a notice from GitHub about participating in the "GitHub Developer Fund", it's a scam. The repository has been blocked by GitHub at this point, but because the scammers directly mentioned visible/successful developers, they'll be more likely to get into your inbox.
![Screenshot of an scam email from “gitcoin-community[bot]” titled “$15M GitHub × Gitcoin Developer Fund 2025”. The message announces a $15M GitHub Developer Fund in partnership with Gitcoin to support open-source contributors. It describes quadratic funding, a total allocation of $15M USDC, and eligibility for all active contributors. Recipients are asked to verify their wallet using Gitcoin Passport, with a note about a refundable deposit. A highlighted link directs to “https://grants.github.com/apply”.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2vs3i4udcqmyngaqvtpj5ktl/bafkreih4hk46l2lslo5ujr3wpmdnrzltb4vguyxyxhz2cb5auh4gfwjxui@jpeg)
September 21, 2025 at 6:33 PM
PSA: If you received a notice from GitHub about participating in the "GitHub Developer Fund", it's a scam. The repository has been blocked by GitHub at this point, but because the scammers directly mentioned visible/successful developers, they'll be more likely to get into your inbox.
Can you imagine trying to build the Hoover Dam without Linear or the Apollo missions without git?
September 16, 2025 at 7:54 PM
Can you imagine trying to build the Hoover Dam without Linear or the Apollo missions without git?
"FTC Probes Whether Ticketmaster Does Enough to Stop Resale Bots"
Narrator: They don't.
Narrator: They don't.
September 15, 2025 at 8:49 PM
"FTC Probes Whether Ticketmaster Does Enough to Stop Resale Bots"
Narrator: They don't.
Narrator: They don't.
The overall goal is to support the shape of the spine, essentially. But the right answer depends on exactly where the pain is. If it's in the L1-L5 vertebrae range (picture attached), something like a rolled-up towel or support cushion will help.
September 13, 2025 at 10:33 PM
The overall goal is to support the shape of the spine, essentially. But the right answer depends on exactly where the pain is. If it's in the L1-L5 vertebrae range (picture attached), something like a rolled-up towel or support cushion will help.
Helpful LLM: I wrote a prompt, spawned two subagents, and 204 seconds later Cline has trawled BLS datasets, extracted the correct dataset, rendered a chloropleth, and uploaded it to S3 for me.
September 4, 2025 at 8:53 PM
Helpful LLM: I wrote a prompt, spawned two subagents, and 204 seconds later Cline has trawled BLS datasets, extracted the correct dataset, rendered a chloropleth, and uploaded it to S3 for me.
The Pandemic Mitigation Collaborative currently estimates that about 1 in every 55 people (~1.8%) is infectious with SARS-CoV-2.
Perfect timing for everyone going back to school.
Perfect timing for everyone going back to school.
September 4, 2025 at 2:51 AM
The Pandemic Mitigation Collaborative currently estimates that about 1 in every 55 people (~1.8%) is infectious with SARS-CoV-2.
Perfect timing for everyone going back to school.
Perfect timing for everyone going back to school.
Current status writing my own kernel drivers:
September 3, 2025 at 12:46 PM
Current status writing my own kernel drivers:
Windows 95 is three decades old this month.
From left to right, here are the floppy stacks you could have used back then to install MS-DOS, Windows 95, and Microsoft Office respectively.
For the current generation of Windows, it would take approximately 3,600 floppies to install.
From left to right, here are the floppy stacks you could have used back then to install MS-DOS, Windows 95, and Microsoft Office respectively.
For the current generation of Windows, it would take approximately 3,600 floppies to install.
August 28, 2025 at 8:46 PM
Windows 95 is three decades old this month.
From left to right, here are the floppy stacks you could have used back then to install MS-DOS, Windows 95, and Microsoft Office respectively.
For the current generation of Windows, it would take approximately 3,600 floppies to install.
From left to right, here are the floppy stacks you could have used back then to install MS-DOS, Windows 95, and Microsoft Office respectively.
For the current generation of Windows, it would take approximately 3,600 floppies to install.
One example of where this played out in real life is in the chart below.
At one point in 2020, the NAV premium of this firm, which was substantially just holding Bitcoin, was $7. That means that if you wanted to buy $1 of this firm's assets, it would cost you **$8** per share.
At one point in 2020, the NAV premium of this firm, which was substantially just holding Bitcoin, was $7. That means that if you wanted to buy $1 of this firm's assets, it would cost you **$8** per share.
August 28, 2025 at 12:53 PM
One example of where this played out in real life is in the chart below.
At one point in 2020, the NAV premium of this firm, which was substantially just holding Bitcoin, was $7. That means that if you wanted to buy $1 of this firm's assets, it would cost you **$8** per share.
At one point in 2020, the NAV premium of this firm, which was substantially just holding Bitcoin, was $7. That means that if you wanted to buy $1 of this firm's assets, it would cost you **$8** per share.
Anthropic presents an 11% attack success rate as a victory:
"When we added safety mitigations to autonomous mode, we reduced the attack success rate of 23.6% to 11.2%."
Isn't "one out of every nine prompt injection attacks succeed" objectively horrifying, and not something to celebrate?
"When we added safety mitigations to autonomous mode, we reduced the attack success rate of 23.6% to 11.2%."
Isn't "one out of every nine prompt injection attacks succeed" objectively horrifying, and not something to celebrate?
August 27, 2025 at 2:02 AM
Anthropic presents an 11% attack success rate as a victory:
"When we added safety mitigations to autonomous mode, we reduced the attack success rate of 23.6% to 11.2%."
Isn't "one out of every nine prompt injection attacks succeed" objectively horrifying, and not something to celebrate?
"When we added safety mitigations to autonomous mode, we reduced the attack success rate of 23.6% to 11.2%."
Isn't "one out of every nine prompt injection attacks succeed" objectively horrifying, and not something to celebrate?