On "Friends," Mr. Zelner interviewed Rachel for her job at Ralph Lauren.
The interview appears in Season 5, Episode 17, "The One with Rachel's Inadvertent Kiss." Rachel is pursuing a fashion career after working at Bloomingdale's, and the Ralph Lauren position represents a major step forward for her. During the meeting, she misreads Mr. Zelner's body language and kisses him on the cheek, creating one of the episode's central comic misunderstandings.
Mr. Zelner is not Ralph Lauren himself. He is an executive at Polo Ralph Lauren and becomes Rachel's boss after she gets the job. The character returns later in the series, including when Rachel is fired after he overhears her discussing a possible Gucci opportunity. That later appearance confirms his role in Rachel's Ralph Lauren storyline.
A common mix-up is to answer "Ralph Lauren," because the interview is for the fashion company and the real designer is referenced throughout the show. The named interviewer, however, is Mr. Zelner, played by Steve Ireland.