

Does a senior mechanic need to understand the physics of piston design to be a great mechanic
I would argue that if senior mechanic doesn’t understand the physics of piston design at least on some degree he’s not a great mechanic. Obviously mechanic doesn’t need understanding on metallurgy, CAD models and a ton of other deeper level stuff just like an IT engineer doesn’t need to know on a deep level how circuit boards are designed or how CPU die manufacturing process works. But both benefit greatly when they understand why something is built the way it is.
I’m also an systems engineer of sorts and have worked with software engineers. And I’ve had requests like “Can’t you just set 'bind-address = 0.0.0.0 on mysql-server and disable firewall” on a directly internet-facing machine and then received complaints when I’m “making things more difficult” from “senior software” -titles. Sure, I can’t write the code they’re doing, or at least it would take me a crapload of more time to do that but on the other hand there’s guys who have so very narrow understanding on anything they work with that it makes me wonder how they can do their work at all in the first place.
Of course no one can master everything in any field but I find it concerning that a lot of guys just press the buttons more or less randomly until their thing works without any clue on what they actually did and how it might affect on different parts of the house of cards they’re building.
Same principle works with IT. I do and have done sysadmin stuff for quite a while and there’s always some random software or whatever I’ve never heard of and someone comes and asks me to fix it. Then you start to ask questions, “what exactly doesn’t work”, “can you show me what you’re doing”, “what should happen when you press that button”, “can you show settings on that thing” and so on. Then you can start to dig down, does the server they’re using respond to ping, does DNS resolve (it’s always DNS after all), does that thing work on the next workstation, when did the problem appear and was there some other maintenance or changes going on at that time and so on.
Same principle, just start to reason the whole thing from bottom up, check everything you come across untill you find something which doesn’t work and then do what’s needed to fix that, rinse and repeat until the problem goes away and make sure that what you’re doing won’t cause new problems. Just the tools are different, the mindset is more or less the same.