Explore shared the full active set with Recent/For You and leaned on freshness,
so it read like a reshuffled Recently-added. Give it a discovery identity:
- Weights: drop freshness (0.25 -> 0.12) and bump novelty (0.30 -> 0.35) so
recency stops dominating and topic-novelty leads.
- Add a soft followed-author penalty (weight 0.3): the scorer now reads
subscriptionAuthors from the Explore runtime and deprioritizes creators you
already follow, so non-followed creators surface ("new to you"). A penalty,
not a filter, so the feed stays full if you follow lots of people.
- More variety: lower the diversity sorter's MMR lambda (0.7 -> 0.5).
Also compacted For You's subscriptionAuthors reader to a one-liner to stay
under feedCoordinator's size cap while adding the same reader to Explore.
Tests: explore follows-penalty scoring; existing explore-scorer/diversity +
feedCoordinator suites green.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
For You shared the full active set with Recent/Explore and only re-ranked by a
blended score, so when a user's signals were thin it collapsed toward freshness
and looked identical to Recently-added.
Give it a structural identity:
- The scorer tags each item forYouTier: 2 = followed author, 1 = interest/
watch-topic match, 0 = other.
- The sorter leads with tier (your people first) regardless of raw score, then
ranks within tier; trusted-muted still sinks last.
- When NOTHING is tiered (logged-out / no follows / no interests) it falls back
to an author-interleaved discovery order (new interleaveByAuthor) so the feed
never reads as a chronological clone of Recently-added.
Tests: tests/for-you-tiering.test.mjs (tier beats score, tiers stack, muted
last, no-signal interleave, scorer tier tagging). Existing for-you-scorer suite
still green.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
The For You feed was chronological, hashtag-interest-EXCLUSIVE, and ignored
follows entirely (docs/feed-algo-audit.md). Now it is inclusive + ranked:
- createForYouScorerStage scores each video: follows-boost (author you follow)
+ interest/watch-topic affinity (cosine vs your interests+watch-history vector)
+ freshness - disinterest penalty. Reuses Explore's vector/similarity helpers.
- createForYouScoreSorter ranks by that score (muted last, recency tiebreak).
- For You pipeline: interests now BOOST not exclude (enforceInterests:false);
scorer added; chronological sorter replaced. Never empty (falls back to
recency when you have no follows/interests/history).
- buildForYouFeedRuntime now feeds subscriptionAuthors + watchHistoryTagCounts.
Watched/blocked/muted are still removed (suppression/blacklist/moderation
stages unchanged). Cheat-resistant tests (older boosted items only win via the
boost). Grid renders end-to-end (~1.3s). Weight tuning is a follow-up.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
