“Do you ever change this type of trade?”

I was sat on the trading floor discussing a new feature that I was implementing with the person who would be using it the most.

“No, never.”

This was one detail of the change that would have far-reaching consequences in the code. A “no” would mean a few days of development, a “yes” would indicate several weeks.

“Are you absolutely sure? You don’t change it even once a month?”