Ask HN: What have you built with the o1 API?

I am curious what people have built with the latest (October 2024 or later) wave SOTA models like the reasoning-based o1. Especially because the reasoning-based models like o1 are more expensive but they must have almost certainly opened up some new use cases.

Although it would also be interesting what new use cases have been opened up by the October 2024 update to Claude 3.5 Sonnet. This "newsonnet3.5" is the only "conventional" model that seems to be able to keep up with the reasoning-based o1 on some tasks although I remember skimming something on X/bluesky that newsonnet3.5 uses some lightweight reasoning internally.