```json
{
  "criteria": {
    "c1": "not_met",
    "c2": "not_met",
    "c3": "not_met",
    "c4": "not_met",
    "c5": "not_met",
    "c6": "not_met"
  },
  "note": "The response suggests sharding all tables by created_at without proper query-workload justification or analysis of single-shard vs. scatter-gather queries. It fails to address timeline mitigations, follower count strategies, external search indexing (proposing SQL LIKE instead), and key tradeoffs such as hot spots."
}
```