All of the above, plus - A senior engineer sees the big picture more readily, and understands the negative as well as positive impact of a change. In any deci

All of the above, plus - A senior engineer sees the big picture more readily, and understands the negative as well as positive impact of a change. In any decision there's seldom one "absolutely right way". Usually it's a case of which compromises are the easiest to live with. Being able to see "both sides" and being able to see beyond the immediate is a key attribute. Here's a hypothetical example - a Junior programmer wants to switch the development team to using Linux, because "there are lots of advantages to doing this". A good senior would ask the question - "ok, tell me why we _shouldn't_ switch?". There are, of course, disadvantages to switching (just like there are advantages and disadvantages to any decision). To show that you understand _both_ sides of the decision is critical. It's not enough just to know the positives, you have to understand the negatives as well. In my experience you will get all kinds of advice to "absolutely do this". But when quizzed the reasons for _not_ doing something have not received the same level of thought. Folks who can see the big picture, and see the long-term impact of a decision, make better decisions. [Of course the junior may be right, in the sense that it may be a good thing to switch. the outcome of the decision is not my point, it's the consideration process that I see as a differentiating factor.]