Guides
Evergreen explainers on randomness, identifiers, and test data — the questions behind the tools, answered plainly.
- How to Generate Realistic Test Data (Without Using Production Data) A practical workflow for generating fake data for testing: why copying production is risky, what synthetic-by-construction looks like, and how to seed it.
- Is an Online Coin Flip Actually Fair? What 'fair' means for a coin flip, why small samples look skewed, and how physical coins compare to a software random flip.
- Random, Pseudorandom, or Cryptographically Secure? What 'Seed' Actually Means PRNGs, seeds, and CSPRNGs explained plainly: when determinism is a feature, when it's a security hole, and how to pick the right one.
- UUID v4 vs UUID v7: Which Should You Use? UUID v4 is fully random; v7 is time-ordered. Here's the bit-layout difference, why it matters for database index locality, and when to pick each.