I wouldn't work for Microsoft for any amount of money. I would not want my name associated with any of the crap they put out.
For me, process control is what I like to do. I have no interest in accounting, reading records from one file and writing them to another and adding them up is just plain boring.
The first process control job I tackled was building a machine to tune quartz crystals to frequency by evaporating gold onto them. I wrote the whole system in HP mini assembler code. It almost got me fired though because I added a little extra feature to the program. Getting people enthused about using a machine is sometimes difficult, so I programmed the paper tape reader clutch on the machine to play the Yellow Rose Of Texas when the machine had tuned 100000 crystals and put out the word to the techs. All the techs wanted to be the one to have the machine play music. Unfortunately, my boss did not see the humor.
It was a good career for me, but I would have been perfectly happy in life as a blacksmith. I prefer working alone, or running a team if thats not possible, so thats the way I structured my employment.
In the 90's, I worked for a computer consulting company (Computer Aid Inc). I was the only PC programmer, all the rest (over 100) were mainframe cobolers. I was assigned the task of creating a data collection system which would multi-task 30 terminals, collect data and interface with an IBM 360 mainframe for Carpenter Technology (CarTech). My boss at the time asked me how I would do it. I told him I would write a multi-user multi-tasking operating system, a computer language and a compiler so the customer could easily customize it as needed. His face turned red and he stormed away. Cobol programmers cannot do such things, and the only reason he didn't fire me was because he couldn't figure out how to do the job. To make a long story short, I started on Dec 7 (Pearl Harbor day) and installed it on the following May 5 (Mothers Day). It ran for 13 years before they replaced it and no one ever found a bug in it. It went so well that the company I worked for sold it to several other steel mills. I ended up getting a $4000 bonus for it.
So tell your son to always think outside of the box. It always works for me. Accounting programmers and web designers are a dime a dozen so tell him to dare to be different.
I would also advise him to also have a physical pursuit to balance out the cerebral. Balance is important in life.