We have real-time conversion of currency but that's not how most customers work. They actually use constant currency: a fixed rate that will be used e. g. for a quarter, a half year, or even a whole year.

This requires keeping track of what currency exchange rate was used from date X o date Y.

PRD: https://docs.google.com/document/d/1itqNBGfHETNrpqrh8bKnd38VC22iOWmKU5nb6y-h_E8/edit?tab=t.0#heading=h.sdhov05ddhog