Before this: Hand off a cleaning job: rules, exceptions, reconciliation
The idea
Read the brief twice, list assumptions where it is silent, and state them in your submission.
Deliver code that reruns, a clean table, an exception report with counts and a short note on decisions and trade-offs.
Time-box polish; explicit reasoning scores higher than extra features.
Worked example
Input: brief silent on duplicates
- Visual
(document) Assumptions → survivor rule stated
- SQL (DuckDB)
-- assumption: latest version per (order_id, line_id) wins
- pandas
# assumption documented in README
Result: Reviewer sees the rule and why
Common mistakes
- Hidden assumptions.
- No reconciliation.
Check yourself
What should you do when the brief is silent?
State an assumption, apply it consistently and mention alternatives.
Practice it
Clean an order-line export.