ULID Universally Unique Lexicographically Sortable Identifier
128-bit identifier: 48-bit timestamp + 80-bit random. Lexicographically sortable (IDs from the same ms sort in creation order). Alizain Feiman, 2016.
Encoded in Crockford Base32 → 26 characters, URL-safe, case-insensitive. Pitch vs UUID v4: sortable + indexes better in DBs (BTree-friendly). Vs Snowflake: no worker coordination needed. UUID v7 (2024 standard) does the same in UUID format → convergence, ULID losing some usage. ULID popular in: many small projects, MongoDB environments. Library support: Python ulid-py, JS ulid, Go oklog/ulid.