[mcguire]

Bridges are not the only things Professional Engineers are involved with. Aviation manufacturers, who often do exactly the kinds of things you describe, have Designated Engineering Representatives (weirdly, not required to be a PE) who is responsible for signing off on the airworthiness of equipment.

Further, losing your license is not the only or the worst consequence. (https://scholarship.law.edu/cgi/viewcontent.cgi?article=3165...) You also assume a civil liability which would be hard to prosecute for a non-licensed software engineer.

(And yes, if the 737 MAX 8 thing is officially reported to have a significant engineering failure, some DER is going to have a very bad day.)