Free practice · Original fictional data
Choose a brief, use the supplied material and hand over a result another person can review. Each task has a smaller warm-up if you need it.
Start with a deliverable
CSV / spreadsheet · About 25 minutes
Clean 68 fictional order records, account for conflicting keys and invalid dates, and deliver a checked CSV with a review note.
Clean order CSV + exclusion checklist + checked handoff report
Open the task brief →SQLite · About 35 minutes
Reconcile paid sales and posted refunds with SQLite. Handle repeated receipts, orphan refunds and over-refunds before exporting a regional ledger.
Replayable SQL + regional ledger CSV + reconciliation report
Open the task brief →Guided review form · About 10 minutes
Compare an overstated pilot summary with three source notes. Enter supported findings in plain fields and download a checked evidence handoff.
Corrected results fields + cited source IDs + review handoff
Open the task brief →Suggested times are planning estimates. All practice runs locally in your browser. You can keep working or download the material for later.