@nvrslps The good Engineer = المهندسة الجيدة The Engineer is good = المهندسة جيدة i.e. if the Adjective is in the same gender, number and definiteness as the Noun (both Engineer and Good are definite / have an 'Al'; are singular; and are feminine) then the adjective defines the noun. Ergo, "The good Engineer". When you put an indefinite adjective after a definite noun, then the adjective does not define the noun. (Because remember the above, the adjective has to have the same gender, number and definiteness to define the noun). The Definite Noun + Indefinite adjective then becomes "The Noun is adjective". Hence the second sentence above = "The Engineer is good". Hope this makes sense, and is of help.
Many things. A good engineer, a boss, a student, your neighbour, an American, a Briton, an Indian....
When people see sentences like
المهندسة مهندسة جيدة
they ask why does this not mean "The good engineer"?
Some would be perplexed why "muhandisa" is repeated, and why one has "Al" and other doesn't?
But if you are solid on the grammar of the given sentence "The engineer is an engineer", you won't have any doubts or issues with the more difficult variants.
That's what I think.