I think more than the specific prompts, I would be interested in how they came up with them. Are these system prompts being continuously refined and improved v

I think more than the specific prompts, I would be interested in how they came up with them. Are these system prompts being continuously refined and improved via some rigorous engineering process with a huge set of test cases, or is this still more of a trial-and-error / seat-of-your-pants approach to figure out what the best prompt is going to be?