A few years ago me and a bunch of friends rented a big Airbnb with a no dogs policy. Some other friends were in the same town, with a dog, and came over and hung out in the yard for a while with their dog. The dog also briefly went in the house (which I think is poor form, to be clear). Somehow the Airbnb host was in the neighborhood and drove by the house to check on it, saw the dog, and then messaged Airbnb to complain.

My friend counter-complained to Airbnb that the host was surveilling us. And the end result was that Airbnb discounted the Airbnb by 50% (over $1000). The owner got nothing out of it. Very surprising to me.

In more detail: in recent years there has been an effort to formalize mathematics using Lean and similar "theorem provers". You write your math proofs in a form of textual source code that Lean can verify for truth. But now Claude Code can produce source code to solve software problems (write me a tool that does X) and also produce source code to solve math (write me a Lean file that proves Y). Historically the main goal of math was to be solve big problems, but now Claude Code can do it. So what does a mathematician do?

Again, I think it's a more dire situation than for software because merely writing the code was never the full job. But for math writing the full proof kind of was.

> As far as I can tell, C89 did not use performance as a justification for any of its undefined behaviors. They were non-portabilities, like signed overflow and null pointer dereferences, or they were outright bugs, like use-after-free. But now experts like Chris Lattner and Hans Boehm point to optimization potential, not portability, as justification for undefined behaviors. I conclude that the rationales really have shifted from the mid-1980s to today: an idea that meant to capture non-portability has been preserved for performance, trumping concerns like correctness and debuggability.

https://research.swtch.com/ub

This is absolutely not true.

Related, Matt Levine has recently been writing about how the AI labs are paying huge amounts of money to tech/math/AI people but these people don't actually know how to spend it. https://www.bloomberg.com/opinion/newsletters/2026-09-10/dal... As opposed to the typical finance worker who knows very well how to spend.

My understanding is that this workload is very uncommon: the Tailscale blog says they used a custom unusual configuration to have many checkpoints like this. So without knowing the bug, it seems unlikely one would build this workload and then find the bug. If that makes sense.

Edit: just want to say that you being able to repro it is awesome, but that the overall claim seems a little overstated to me.

I think yours works. Alternatively in the loop:

    if out.len() < n {
        out.push(0);
    }
    out[n] = x;
    n += (x > threshold) as usize;

In general if you want a no-internet 1 hour in the morning, organize yourself to wake up 1 hour earlier (maybe going to sleep 1 hour earlier). You sleeping until 8am, and you sleeping until 7am and having no internet for 1 hour, is equivalent to the outside world.