I've coded the firmware for a CAN-based communication bus for a medical device with lots of different boards talking to each other. This same company had a war industry department and they used this code in a missile project. It left a weird taste in my mouth.

Btw, they got an early version that had a memory leak, and when I went to warn them, they just said: "It's okay! It's just going to run for about 20 seconds!"