optimist vs doer

optimist and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
optimist	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of optimist; that is, doer is a word with a broader meaning than optimist:

Other hypernyms of optimist include actor, worker.

optimist (noun)	doer (noun)
a person disposed to take a favorable view of things	a person who acts and gets things done