Ask HN: What are your favorite examples of novel multi-domain projects?

A month ago, I read this article about the science behind crispy food (https://news.ycombinator.com/item?id=22458358).

From organic chemistry to refine food texture, psychology and marketing to highlight appealing qualities, and audio engineering to perfect the sound of the “crunch,” I found this to be a fascinating example of several diverse fields culminating in a unique and functional application.

We regularly encounter specialization crossover in our professions; what situations or projects stand out to you the most?