I've been building a personal website service [1] as an alternative to social media. I hadn't heard of POSSE, but I call my idea "Write once, share everywhere" - the idea being that your content should live on your site, but can be shared on other social networks.
A tip for anybody building POSSE systems: OpenGraph images make a huge impact on engagement on social networks. I generate images on-the-fly with the post title and some images, which makes links take up much more space on feeds.
A tip for anybody building POSSE systems: OpenGraph images make a huge impact on engagement on social networks. I generate images on-the-fly with the post title and some images, which makes links take up much more space on feeds.
[1] https://postcard.page