[jamesjporter]

In the spirit of noelwelsh's comment above, we could say that the "trades" are things like "writing webapps" or "writing control software or airplanes" or "writing simulations of chemical systems."

"Solving problems with computers" is too broad for any one person to master all aspects of it. There are so many different kinds of problems! Many of them also involve domain specific knowledge that has nothing to do with computers or computation (my airplanes and scientific computing examples above).

[acuozzo]

> we could say that the "trades" are things like "writing webapps" or "writing control software or airplanes"

People don't usually __die__ as the result of a bug in a webapp, but they can as the result of a bug in airplane software. I claim that a NomadicProgrammer™ (armed with "Learn Ada in 24 hours!", of course) would be __dangerous__ if tasked with work in this "trade".