“I didn’t really care if they branded me a troublemaker,” she says, “because I hadn’t gotten that far in my life and overcome all these things to get treated inappropriately. I wasn’t going to take it. I’d worked so hard. I deserved so much better. And I was, like, ‘No. That’s not O.K. You don’t get to do that.’”

In her memo, she says, “I knew I had to be super-careful about how I said it if I wanted anybody to take it seriously. A lot of women have been whistle-blowers in the past, and a lot of them have just gotten torn down and treated terribly. One of the things that kept popping up was this idea that if you do whistle-blow about sexual harassment, then that is what will define the rest of your life. And I kind of struggled with this. But then, to me, I realized, you know what? No. Stepping back, just being in my little Stoicism Susan bubble, if what people know you for is bringing light to an issue about bad behavior, about bad stuff going on and laws not being followed and people being treated inappropriately, why wouldn’t I want that? That’s a badge of honor.

“And I wasn’t just standing up for myself. I felt like I was standing up for everyone else that I was seeing at Uber who was mistreated. It was an extremely demoralizing environment. I would see people who would get harassed or made fun of or bullied and they would go report it, and they would just get ground down by upper management and H.R. And so I felt like, if I can take this on despite the consequences, then I should do it.”

Like women in Hollywood I talked to after the Weinstein collapse, Ms. Fowler thought the new outspokenness in Silicon Valley on sexual harassment may have been spurred by the election of President Trump.

“The second Trump won, I felt super-powerless and I thought, ‘Oh my God, no one’s looking out for us,’” she says. “They have the House, they have the Senate, they have the White House. And so we have to take it back ourselves. We have to be the ones doing the work.”

The only woman on the board then, Arianna Huffington, who had vowed that the culture of “brilliant jerks” must end, had been trying to help Mr. Kalanick by advising him to sleep more and meditate. But he caused another kerfuffle when he chose to meditate in the lactation room.