I saw that there was a pull request for a rate limiting feature for Ktor a while ago, but it recently became closed because it got stale. I have done my own rate limiting feature. Is there a high demand for such feature in Ktor? Should I consider doing a PR?

Yes please. If you already have taken the effort, add it to the whole eco system.

All right, will try to open a pull request during the day 👌

I would also consider using a rate limiting feature

I have never made a PR against ktor before, and it was a bit more daunting than anticipated. I will try to get it done as soon as I have time, but I might not be able to submit it today.