I think this post is the best place to "promote" my open-source pet project

It converts any dynamic website to rss feed

It's self-hosted and stateless

https://github.com/Egor3f/rssalchemy

It's however not in active development state, but if there will be some pull requests I'll review them, so it's not abandoned

Demo page is not working now, but if there will be some activity, I'll bring it back up