I created/deployed a system to track a fleet of aircraft in real-time, that then messaged individuals when anomalous conditions (plane crash) was detected. It was inexpensive to run and reliable.

In terms of what's most gratifying though, honestly, giving workshops or volunteering in a way that empowers others. I give workshops to trans and gender diverse individuals. I've volunteered with Technovation to get young women into tech. I've done one-on-one mentorship. That's the stuff that makes me feel better and none of that is paid work.