[StavrosK]

Yeah, exactly. You'd need to go to one of the big companies to need those skills, so you usually get companies who want some sort of API glued together with off-the-shelf components, mainly because smaller companies are much more numerous than larger companies and off-the-shelf is good enough at small scale.

This wouldn't cut it at the companies you mention, I agree. I think the main thing is that the actually valuable skills (being able to figure things out on your own, having an intuitive sense for when a solution is suboptimal even when you don't know the optimal solution, knowing design patterns, etc) are transferrable, so a good developer could work on either thing.

It probably wouldn't take two hours to become acclimated, but after a short ramp-up period, they'd be pretty good at it.