Interview Guides
You are given retailer inventory feed snapshots and shopper-facing inventory snapshots from Instacart. Write a PostgreSQL query that identifies SKU-level mismatches between the latest retailer feed record and the latest shopper-visible record for each retailer_id, warehouse_id, and sku_id on the same calendar day. Return only rows where the quantities differ or one side is missing, and include a mismatch reason that distinguishes feed_only, app_only, and quantity_mismatch.
