Currently we have a engineer with 7 questions.
Do we really need that?
It's not clear what the engineer tag is supposed to mean, and the questions currently tagged with it don't really seem to have anything in common. Specifically, there are:
So I don't see any reason to keep the tag.
(The flight-engineer tag, on the other hand, does seem like it may be useful, so let's keep it. Maybe we should apply it to more questions, even.)
No we don't. There are multiple engineering disciplines involved in aviation, most of which have dedicated field/topic tags, such as structures, avionics, propulsion, aerodynamics, etc.
And since career advice is both too broad and opinion based, using the tag for such purposes combined with a topic-tag is pointless.
We do have pilots so maybe we'll have a similar use for engineer on future questions but right now it doesn't seem to be very useful. There are only a couple questions there that seem to really fit the tag at all and career seems like it is close enough for most use cases.