To be fair, the data scientists rarely have the foresight to know what the data scientists need the information for. The only time I've seen a data scientist correctly include all the data they needed (but still be wrong) was when they answered "All of it. We need all of the data".
And you can't build a time machine to go and get it once you do know. Want X days of historical data for training/backtesting and we just implemented the metric this sprint? Good luck meeting your deadline!
