Demo project (sample data): a

Demo project (sample data): a Python ETL pipeline that takes messy CSV and JSON files (duplicates, mixed date formats, inconsistent casing, missing prices), cleans and validates them, writes failed rows to a rejects table with a reason instead of dropping them, and loads a star schema (fact + 3 dimensions). A reconciliation check confirms every input row is accounted for. On the sample run: 5,108 rows in, 108 duplicates removed, 315 rejected with reasons, 4,685 loaded.