Tarses has pointed to her ease with writers, finding script flaws and suggesting improvements, as her strong suit. She also gained a reputation for tough decisiveness; in 1991, as a junior programming executive, Tarses (then using her married name, McDermott) even declined to recommend that NBC pick up "Baltimore", a sitcom pilot about jazz musicians, produced by her own father.

Born in Pittsburgh, Tarses was raised in Los Angeles' less than trendy San Fernando Valley. After graduating with a theater degree from Williams College, she entered showbiz as a glorified production assistant, more specifically, the Assistant to the Talent Executive on NBC's "Saturday Night Live". This valuable experience helped Tarses land a job as a casting director at Lorimar Productions. She joined NBC in September 1987 as manager of Creative Affairs for NBC Productions segueing to the more high-powered Entertainment division in December as manager of Current Comedy Programs. In this capacity, Tarses served as NBC's program executive on such sitcoms as "Cheers", "Amen", "A Different World" and "227". By July of the following year, she was named manager of Comedy Development for NBC Entertainment. February 1989 found Tarses as the director of Comedy Development. In this capacity, she participated in the development of such ratings winners as "Wings", "Blossom" and "The Fresh Prince of Bel-Air". (Her brother Matt Tarses served as a writer and story editor on the latter sitcom late in its run.)

As senior vice president of Primetime Series for NBC Entertainment, a position she assumed in 1994, Tarses reported directly to her mentor Warren Littlefield, president of the division. She was credited with playing a major role in the development of such hits as "Friends" and "Frasier" while supervising existing shows. Tarses was reportedly approached by former CAA head turned Walt Disney Company president Michael Ovitz in February 1996 with a dream job offer--the presidency of ABC Entertainment. The NBC brass acted quickly, placing Tarses on hiatus until June while she pondered her immediate future. They didn't want her taking part in plans for the following (1996-97) season lest she be able to take insider knowledge to the competition.

Rumors abounded during this period, most notably, that Tarses had requested release from her two-year contract on the grounds of sexual harassment by her NBC superior, West Coast president Don Ohlmeyer. (Under a confidentiality agreement with NBC, she has refused to comment on the story but sources supposedly close the Tarses and other top NBC brass have denied it.)

Tarses moved to ABC in June of 1996. Although she had no input in the Fall 1996 lineup (which fell into third place), she would put her stamp on the midseason. After a very rocky tenure that saw the network fall to third place in the 1998-99 season, top brass brought in Lloyd Braun, the head of TV production at Disney as co-chair, to serve alongside Stuart Bloomberg. Although Tarses and Bloomberg had a workable relationship when Braun was added to the mix, she was reported to have felt snubbed by his appointment. VARIETY reported that tensions between Tarses and Braun--according to an August 27, 1999 article, Tarses "often failed to acknowledge Braun's presence if the two passed each other in the hallway" and her staff was purportedly afraid to note his presence as well out of fear of angering their mercurial boss. When top executives told the three that the new structure was to work, Tarses opted to resign, with roughly two years remaining on her original contract. Despite her uneven tenure at ABC, she would undoubtedly rise phoenix-like in another executive position.