Developer Guides
Practical guides on test data, international address formats, postal code systems, and safe testing practices — written for developers and QA engineers.
What Is Test Data? Synthetic Data for Development and QA
A practical introduction to test data: what it is, why synthetic beats real customer records, and how developers and QA teams use it day to day.
Last updated: 2026-07-26
Address Formats Around the World: A Developer’s Field Guide
A practical tour of international address formats — field order, locality concepts, postal code shapes — and how to test forms against all of them.
Last updated: 2026-07-26
ZIP, Postcode, PLZ: Postal Code Systems Explained for Developers
A developer’s tour of postal code formats worldwide — numeric, alphanumeric, and none at all — with practical validation and storage guidance.
Last updated: 2026-07-26
Test Card Numbers and the Luhn Algorithm, Explained
How the Luhn checksum works, what it does and doesn’t verify, and when to use generated test card numbers versus official provider sandbox cards.
Last updated: 2026-07-26
Using Generated Identities in E2E Tests (Playwright & Cypress)
Practical patterns for feeding generated names, emails, and addresses into Playwright and Cypress suites without flakiness or collisions.
Last updated: 2026-07-26
Why You Should Never Test With Real Customer Data
Production data in dev and staging is a breach and compliance risk. The case for synthetic test data, plus a practical policy your team can adopt today.
Last updated: 2026-07-26