One year ago, agents could barely generate a landing page. Now, they can build entire apps and prescribe medication (…in Utah) . How did we get here? A few months ago, it felt like things might finally be slowing down.
Now, things are moving faster than ever.
To understand what’s going on, it helps to understand what an accelerometer is.
The Accelerometer
Perhaps obviously, the accelerometer measures acceleration.
In high school, you were taught how to convert acceleration to current velocity, or even total distance traveled. It’s pretty easy. You just need to take the integral (or double integral, respectively)
According to the physics you learned, that little accelerometer is not just an acceleration sensor. It is also a velocity sensor, AND (even more impressively) it is a position sensor!
But unfortunately, you were taught lies. While accelerometers can kind of measure velocity, they can’t measure position at all.
The problem comes down to one tricky fact: the sensor has error, and the error accumulates every second.
For years, agents suffered from a very analogous issue. They were incapable of running for more than a few seconds in any meaningful way… because error compounded at every step.
If any step had an error — a false assumption, a misinterpretation, whatver — the agent was largely incapable of recovering. It went about as well as a Roomba trying to vacuum fresh dog poop.
Because error compounds, the inverse is true: very small reductions in error rates have out-sized benefits. And that’s exactly what happened.
Claude Opus 4.5 passed some critical threshold of one-shot accuracy. e.g. instead of the chance of a mistake being 1/3 → it became 1/5. Because error compounds, this is a big deal.
Models started to be able to detect and clean up their own bullshit.
On any single turn, you won’t notice a huge difference. Going from 65% accuracy to 75% accuracy doesn’t feel very different in practice.
But when error compounds, it makes all the difference in the world.
Addendum: Will it continue?
Probably. But I don’t know. I think it will.
If you think back to that little comic from earlier, it’s worth considering all of the things that can feel like acceleration. Even going in circles can feel like acceleration, because you’re constantly changing direction. I think there are definitely aspects of our current trajectory that does feel a bit like going in circles (writing quality, for example).
But the progress I talk about above is real, and does seem to be accelerating.