In this post I’ll walk through an example of how to convert between currencies. A challenge is that the conversion rate is constantly changing. If you have historical data you’ll want the conversion to be based on what the exchange rate was at the time. Hence the fields you need when doing currency conversion are:
1. Date of transaction
2. Start currency (what you’ll be converting from)
3. End currency (what you’ll be converting to)
4. Price (in units of starting currency)
Bryan also makes the smart move by memoizing the data first, as those API calls can get expensive otherwise.