You are claiming that you know >>all<< operating systems and bootloaders and that >>all<< run only in 32-bit mode - with no exceptions... a big claim about your knowledge...
So you know even all non-public bootloaders and OS-es...
And it may grow even more when some/many US subsidiaries in UK will move to Ireland after Brexit (english speaking country in EU is attracting many US companies)...
For companies with existing technology stacks try to reuse existing knowledge (JNode, Java, .Net, ...).
For companies "starting from scratch": analyse possibilities and make a strategic decision about your technology then try to stay with it and build up the knowledge along the way...
In 1996 I made a decision to use Java everywhere where it is possible and I sticked to that decision up until today, so I prefer Java...
These slides are great! "Standing on the shoulders of giants..." If time-to-market is important, JVM is the way to go... Manually managed memory is for low-level/OS software, GC is for the rest (apps)... with some exceptions...
From the related thread: https://news.ycombinator.com/item?id=12015388
"In today's digital world, it appears to be a virtual certainty that computers accessing the Internet can—and eventually will—be hacked."
=>
"In today's education world, it appears to be a virtual certainty that research information from countries which allow foreign students can—and eventually will—be stolen."
So you know even all non-public bootloaders and OS-es...