You're reviewing a junior engineer's day of work. They posted seven journal entries today. THREE of them are wrong, each in a different way: a misclassified account type, a wrong amount, and a debit/credit reversal. Apply every entry to your ledger, then for each sandbox prompt: find the bad one in the Journal view, then post the corrective entry. This is the forensic capstone, you're learning the three bug shapes that every fintech audit eventually surfaces.