DEVELOPER REPORTS ACTUAL UUID V4 COLLISION

The duplicate UUID in question—b6133fd6-70fe-4fe3-bed6-8ca8fc9386cd—appeared when a new database record was inserted with a freshly generated v4 identifier that matched an existing record from 2025. UUID v4 relies on random number generation to create 128-bit identifiers. The theoretical probability of collision is astronomically low, with odds estimated at roughly 1 in 5.3 trillion for generating two identical UUIDs. The developer confirmed the duplicate wasn't caused by a double-insert bug or other system error, ruling out common causes of apparent collisions. They were using the widely-adopted npm uuid package, a standard library for UUID generation in JavaScript environments. The incident raises questions about randomness quality in UUID generation libraries and whether production systems should implement additional safeguards despite the theoretical improbability of collisions.