Finance asks for a reusable paid-order reporting model. Use the fictional shop sources, keep current order versions, preserve customers with zero paid orders, and deliver a table with a tested customer key. No currency conversion is requested.
Harbor Cart finance needs a report that can survive a source correction without changing its definitions. You'll create staged orders, isolate paid orders, aggregate at customer grain, and preserve customers who haven't placed a paid order. Each step extends the same project. Keep the dependency graph readable so the next analyst can trace the final amount to its source.
The deliverable has one row per staged customer. Amounts stay in their source units; this task doesn't invent exchange rates or combine currencies into a business revenue claim.
The requested measure is simply the sum of the exercise's order amounts. Add tests only after the model has the intended grain. A test is a guarantee about that grain, not a replacement for choosing it.