عرض عملي: تحويل "يجب ألا تضيع الطلبات أبدًا" إلى متطلبات قابلة للاختبار

خطوة بخطوة

1. Start from the sentence and ask the interview questions: lost where, by whom, for how long?
2. Split it: "accepted orders are durable" (RPO) versus "orders are visible within 2 s" (latency) versus "no duplicate charge".
3. Write three scenarios with measures; define "lost" as accepted-but-not-recoverable.
4. Record assumptions (single-region failure is the worst case) and constraints (PostgreSQL stays).
5. Planned mistake: accept "zero loss" as written. Fix: show that it implies synchronous multi-site writes and price it; negotiate "no loss of acknowledged orders after a single-AZ failure".
6. List the conflict (zero loss vs latency budget) with owners.