Estimation & requirements Study Portal

Key takeaways

• Requirements first: 3–5 functional use cases, an explicit out-of-scope list, and only the non-functional requirements that change the design.
• Round aggressively: a day is 10^5 seconds, 1 KB × 1 B is 1 TB.
• Peak = average × 2–10. Size for the peak.
• Storage = count × size × retention × replicas, plus index overhead.
• Cache the hot set (80/20), not the dataset.
• End every number with "this means…" and a design consequence.