What have you worked on that is as cool as a space probe that's cruising in interstellar space and still collecting valuable data?

There are a lot of things as cool as, done by people I know, such as the gyros on the Webb telescope, the APU in the F-35, or a small rack-mountable Cesium reference clock, but there aren't many opportunities like that.

That's the thing. You only have the cool factor, but that wears off very quickly when you are maintaining legacy code and tools and then your collegues are playing with the new hot and shiny toys.

I won't write about the projects I've been involved with for privacy, but to give you an idea some of my old team members were involved in ams-02 for example.