| # | Archetype | Primary Concern | Key Failure Modes |
|---|---|---|---|
| A1 | Search & Discovery | Relevance + latency | FM6, FM8 |
| A2 | Social & Communication | Delivery + fan-out | FM3, FM6, FM7 |
| A3 | Marketplace & Transaction | Correctness + consistency | FM4, FM9, FM12 |
| A4 | Media Delivery | CDN hit rate + storage cost | FM6, FM8 |
| A5 | Data Intelligence | Quality + freshness | FM8, FM9 |
| A6 | Platform & API | Reliability + backwards compat | FM2, FM8 |
Archetype combinations: YouTube = A4 + A1 + A2 · Uber = A3 + A5 + A1 · Stripe = A3 + A6
Seam rule: The boundary between two archetypes is where the most interesting design problem lives.