Score each 1-4 (1 = missing, 2 = shaky, 3 = hire-level, 4 = senior). Hire bar: no 1s, average >= 3.0.
| # | Dimension | What hire-level looks like |
|---|---|---|
| 1 | SQL correctness | Dedup + sessionization correct, explains window framing |
| 2 | Volume math | Back-of-envelope rows/day, storage, runtime — within an order of magnitude |
| 3 | Architecture trade-offs | Names two real alternatives and why they lost |
| 4 | Failure modes | Idempotency + retry + alert story without prompting |
| 5 | CDC/incremental | Watermark vs log capture distinguished; late data handled |
| 6 | Warehouse judgment | Partition/cluster/cost reasoning grounded in the plan |
| 7 | Communication | Structured answer, checks understanding, lands the point |
| 8 | Capstone ownership | Can defend any line in their own repo |
Verdict: Strong hire / Hire / No hire — plus the single highest-leverage fix and a re-mock date when applicable.