With rule #2, (knowledge not transferring), that's always a sign you're not working somewhere good, or you're in a role that will stunt your growth. You really

With rule #2, (knowledge not transferring), that's always a sign you're not working somewhere good, or you're in a role that will stunt your growth. You really should be able to transfer a lot of what you learn. If you're stuck with a bunch of proprietary gunk that does the same thing as open source, but worse, good engineering management knows to replace that stuff because it will inevitably drive talent away. Or at the very least rotate people through those roles. I know I've left jobs where I've been stuck maintaining legacy systems while the rest of the company moved on to open standards because if you do that for years it's like slow career suicide.