Is there an extremely efficient way to get a list of Contacts with a Created_Time in a date range, and then get a count of their completed deals? I was trying to do a join in COQL but the docs are pretty hard to follow on this.

The next thing we need to know is not only how many deals we did for all the contacts in that date range, but what the sales amount was.

We're trying to update a third-party business intelligence dashboard with these statistics. (And yes, we're going to use a cache table between your API and this third-party dashboard.)

My client's deadline on this task is Thursday, 9/24. Can you help me make this deadline?