>>12170032Well, the least saturated are usually either the newest (or currently expanding) and/or the hardest. Manufacturing is well saturated, because it is relatively easy and hardly new. I can say from experience that currently optical engineering is well below saturation - it involves harder-than-usual math, most schools don't offer it, and with the limitations of radio and microwaves, optical communications and sensing are suddenly experiencing a huge demand.
Regardless, remember that today's "unsaturated" can very easily become tomorrow's "oversaturated". It happened in software, certainly, although even RF is still currently in high demand even though optics are drawing heavier.
But honestly, you'll do better chasing your interests and talents. You'll like what you are doing more AND you'll do better at it. The easy path generally ends up making everything else harder.