UUID v4 vs ULID: log-friendly IDs and sortability trade-offs

Pros: simple, extremely low collision risk, broad library support.

Cons: random order; some DB/storage layouts feel more write churn with random PKs (engine-dependent).

Time-ordered prefix helps humans skim chronological order in logs.

Sortability is not secrecy—predictable ordering can leak coarse traffic patterns.

Prefer UUID when you want opaque random IDs; ULID when rough time order helps debugging.

Normalize casing/hyphen rules across services to avoid case-insensitive uniqueness surprises.