[Jnr]

They are probably able to do it with little because they understand what they are doing.

There are too many developers and teams that don't understand the underlying principles and limitations of the technology they use. In a good case those developers get schooled by experienced engineers, but frequently they end up in an important position in some big enterprise software company and makes life miserable for many people.

[actually_a_dog]

I agree. This also ties back to the whole "a junior developer could clone Stack Overflow," or "I could do that in a weekend" mentality.

Sure, maybe a junior dev can make a simple forum, or you could make a web app that duplicates the functionality of SO at low loads in a weekend. But, when you're serving an average of 500 requests per second, you need to know what you're doing. And, IMO, this "knowing what you're doing" is the difference between knowing how to engineer a system and how to write an application.