In a visual novel a girl just said そうですねー and the guy replied
I feel like he's making fun of her for saying desu ne.... and that she sounds like his aunt?
Edit. バイト means "work" in this context.
I feel that Jens' translation is missing the emphasis present in the Japanese text, so here is my version.
I don't think he's making fun of her. ですね just adds a bit of emphasis on 僕, presumably because the conversation was about that girl, and he's switching the topic of conversation to about himself. Then he says 伯母の紹介だったからこそ, which emphasizes that the work came through the aunt, or else he wouldn't be here. So once again, the topic of the conversation right before this must have been why the girl is working here.
I think Jens' translation is unnatural and slightly flawed, and I am basing mine off of Kohsuke Kawaguchi's correct answer, but making the English more natural.
particle: for sure (emphasize preceding word)
【訳】 noun: conclusion from reasoning, judgement or calculation based on something read or heard; reason; cause; meaning; circumstances; situation;
(I translated it as "because")
noun / noun or participle with aux. verb する → conjugation: work (esp. part time or casual) —Abbreviation. From German 'Arbeit'. → アルバイト
【紹介】 noun / noun or participle with aux. verb する → conjugation / noun with genitive case particle の: introduction; referral
Editor's note: "work" means バイト in this context ;)