UuidV7

UUIDv7 (RFC 9562): time-ordered, database-index friendly, and monotonic within the lifetime of the process. The recommended default.

Backed by the stdlib's Uuid.generateV7, whose process-wide generator orders ids minted inside one millisecond by a dedicated counter (RFC 9562 §6.2) and treats a wall clock that steps backwards as "not ticking" — it keeps the last timestamp and counts on — so the order survives an NTP correction too (read off the stdlib's own, internal kotlin.uuid.UuidV7Generator in the 2.3.21 source — not a class of this library's).