peter 25aed6635f perf(feed): a shuffle walks a stored random key instead of sorting the whole scope ...

Every video carries a random number drawn once (videos.shuffle_key, migration 0118, indexed with
id). A seed picks a point on that ring: the feed's Shuffle sort pages along it and wraps, and the
Home surprise reads a 500-video window of it and shuffles that window by the seed, so no video is
favoured for sitting after a wide gap. The md5(id || seed) order read and sorted the whole feed
scope on every call: ~350 ms on prod per surprise, 381-767 ms per Shuffle page on localdev, now
14 ms and 4 ms.

2026-11-07 04:00:00 +01:00

..

baseline.json

perf(feed): a shuffle walks a stored random key instead of sorting the whole scope

2026-11-07 04:00:00 +01:00