Key order is time order.

Snowflakes are minted in time order, and base62 preserves that order byte for byte, so the ordered_set’s key order is chronological order — for free, with no clock column and no sort. EchoData.Timeline turns this into its whole API: latest-N, cursor pagination, and time-window counts are all range operations on the key.

Three reads fall out of one property. Latest-N walks back from the table’s last key; a window is an :ets.select over a half-open range of ids; and a time bound needs no stored id at all, because EchoData.Snowflake.min_for mints a synthetic cursor for any instant — everything since two o’clock becomes a key comparison. The branded id even doubles as the public pagination token: opaque-looking, URL-safe, and exact to resume from.

Codemojex reads its history this way. A room’s recent guesses are latest-N off the keyspace; a leaderboard over the last hour is a window between two synthetic cursors; a feed resumes from the last id the client saw. None of it stores a timestamp, because the id is the timestamp, and the keyspace is already sorted.