Challenge Library
Each challenge asks you to define the key, handle edge cases and explain how you would validate the result.
SQL: Find Missing Scans
Find expected HUs that do not exist in the scanned table.
Open →SQLSQL: Cheapest Supplier per Item
Return the lowest price supplier for each SKU.
Open →SQLSQL: Latest Status per PO
Return only the newest event for every PO.
Open →SQLSQL: Duplicate HU Audit
List HUs that occur more than once with their counts.
Open →SQLSQL: Running Production Output
Calculate cumulative quantity through the shift.
Open →ExcelExcel: Find Missing SKUs
Mark SKUs in list A that do not exist in list B.
Open →ExcelExcel: Price Change %
Calculate price change while handling zero old price.
Open →ExcelExcel: Lookup by SKU + Supplier
Return the price matching both SKU and supplier.
Open →ExcelExcel: Flag Duplicate IDs
Flag every ID that occurs more than once.
Open →ExcelExcel: Supplier Working-Day Lead Time
Calculate working days between order and delivery.
Open →HTMLHTML: Accessible Tool Form
Build a labeled numeric input and a Run button.
Open →HTMLHTML: Results Table
Build a table with accessible column headers.
Open →HTMLHTML: Advanced Options Panel
Create a no-JS expandable panel.
Open →OperationsOperations: Diagnose OEE
Given A=90%, P=80%, Q=98%, identify the biggest loss.
Open →OperationsOperations: Reorder Point
Calculate lead-time demand plus safety stock.
Open →DataData: Diagnose a Broken CSV
A description contains commas and shifts columns. What is missing?
Open →DataData: Profile a New Extract
Choose the first checks before trusting a new 100k-row file.
Open →OperationsProcurement: Invoice Variance
Separate quantity variance from price variance.
Open →OperationsInventory: Stock Coverage
Convert on-hand stock and daily demand to coverage days.
Open →OperationsProduction: Capacity Gap
Compare theoretical daily output with demand.
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