sequencer

This skill should be used when the user needs a "unique ID generator", "distributed IDs", a "Snowflake ID", asks "UUID vs auto-increment", wants a "time-sortable ID", a "monotonic sequence", a "ticket server", or "ID generation at scale". It gives a menu of ID schemes (UUID/ULID, Snowflake-style, DB ticket/range) with their causality, ordering, and clock-skew trade-offs. Use it whenever a design needs collision-free identifiers across many nodes, even if the user doesn't say "sequencer".