&quot;How well do you understand an internal combustion engine?&quot;<p>He is not hiring drivers; he is hiring mechanics and manufacturing engineers. And yes, they both absolutely need to know how an IC engine works.<p>Yes, tools are doing their job, yes they will only keep getting better and I want them to keep getting better. But that is no excuse to not know how they work, and what are the tradeoffs of using one over the other. e.g. There are plenty of ORMs for PHP. Why would you use one over the other? If one ORM generates more efficient queries at the cost of some programming discomfort, I&#x27;d much rather have you choose that.<p>By definition, tools solve generic use-cases. i.e. you can get away with tools as long as you&#x27;re solving simplistic generic problems that have been solved before. But the moment you transcend that boundary and need to do anything custom, especially at scale, you will totally need to know how things work under the hood. You may still end up modifying an existing tool, but you&#x27;ll only do a good job at it when you understand the insides.<p>Also, the urge to look under the hood is simply a proxy to curiosity. That is exactly what starts to separate better  engineers from mediocre ones.<p>[About me: <a href="http:&#x2F;&#x2F;InterviewKickstart.com" rel="nofollow">http:&#x2F;&#x2F;InterviewKickstart.com</a>]