UUIDs are everywhere now. Databases, APIs, distributed systems, event streams, authentication systems, microservices — almost every modern application eventually needs globally unique identifiers. For years, UUID v4 became the default choice because it was simple and highly collision-resistant. But recently, UUID v7 started gaining attention because it solves one of the biggest weaknesses of v4: poor database locality. The interesting part is that UUID v7 is not simply “better.” It depends heavily on your workload, database architecture and scaling needs. Quick Overview Version Generation Method Ordered? Best For UUID v4 Pure random ❌ No Security, unpredictability UUID v7 Timestamp + random ✅ Yes Databases, indexing, distributed systems What Is UUID v4? UUID v4 is the most commonly used UUID format today. It is generated almost entirely from random numbers. Example: ```text id="uuida1" 550e8400-e29b-41d4-a716-446655440000 The important characteristic is randomness.…