Is it a verb? A past tense maker? Which is its function of 了 in this sentence?
曾在新西兰Berger king 做过汉堡，当过收银员。这份工作让我认识到了团队合作的重要
"verb + 了" is used to emphasize the completion of the action.
So "认识到了" means "I have realized".
认识到了 <- Acknowledged, Learned.
The word "了" means past tense "ed".
You might already know that Chinese does not have a lot of grammatical structure. But how do Chinese people make a sentence to mean what past tense and perfect tense? They put a 了 in the sentence (most of the times right after the verb)