When Lynn Yu learned about the opportunity to become CEO of Jason Wu, a luxury ready-to-wear women’s wear brand in New York, she was two weeks postpartum with her second child. You can’t plan for life-changing opportunities, she later said, and Jason Wu came at the most difficult time possible. 

“I thought, ‘This is not the right time to interview—I looked like a balloon,’” Yu, who has been heading up Jason Wu for three and a half years now, recalled to Fortune’s Peter Vanham during an exclusive interview at Fortune Connect last week. “But you just gotta go for it. Luckily, Zoom is just from [the shoulders] up.” 

After several weeks of round after round of “grueling” interviews, she finally got the offer. While Yu says she had some doubts at first, her résumé was bulletproof for joining the luxury women’s wear brand that has been worn by former First Lady Michelle Obama, Reese Witherspoon, Julianne Moore, Diane Kruger, Liu Wen, and Christy Turlington. 

At the time, Yu was vice president of business strategy at Tommy Hilfiger. Before that, she led strategy and client analytics at Chanel, and after graduating from Harvard, she began her career as an investment banking analyst at Goldman Sachs in the U.S. consumer retail sector.

None of that was able to blunt her impostor syndrome, she recalled to Vanham. “I thought, ‘Oh, my God, how do I go from a VP to a CEO? That sounds like a quantum leap.’”

She decided to navigate the transition by taking things as they came, one day at a time—and realizing she shouldn’t compare herself with her predecessor, Eddie Volchko. He had a CV a mile long, with time at fashion houses Badgley Mischka and Derek Lam and two years as company president at Jason Wu under his belt. 

“I felt almost like an intern to him, but he was willing to teach me the ropes,” she said. “I just took it one day at a time, and after a few months, felt more and more comfortable. But it was certainly challenging.”

Leaping to CEO requires a clear vision and a loyal team

For Yu, making the successful leap to CEO requires two things: having a vision and creating a strong team. “People will be judging you based on where you were right before, so you need to have a certain level of conviction in your vision for the brand,” she said. “You then [must] be able to recruit people that truly support you.”

That second piece is vital, she said, because certain people—your new peers or direct reports—may feel jealous of your success, or that they’ve been overlooked in favor of a much younger, greener person who has suddenly come aboard. 

“They may not be the best supporter for you or your career,” she said. “So I think in that case you may have to do a little reshuffling—and stay true to your vision.”

Yu’s vision has always come with grit. Ever since her early finance days, Yu’s technique has always come down to, in her words, being obnoxious until people say yes.

Case in point: When she was an undergrad at Harvard, first developing an interest in fashion, she made connections by calling brands’ customer service hotlines and working her way up. 

“I called Donna Karan’s number and said, ‘I really want you guys to come to the campus and speak to the students at a conference. Please, please, please,’” she recalled. Eventually, the CEO’s assistant took the call and heard her out, but he canceled about a week before his scheduled appearance at Harvard. There was no time to find another speaker, so she called him back and personally begged him to un-cancel.

“And he was like, ‘I’ve just never seen someone who was so persistent and so annoying. So, okay, fine. I’ll say yes,’” Yu recalled. “Then he came, and he spoke, and that was my first fashion connection.”

The experience, Yu said, was formative, and remained top of mind when she took the Jason Wu gig under less-than-ideal circumstances. “Even if it’s a no, then at least I tried, and then I can live with myself,” she said. “But I won’t know the answer until I try.”