On Jan. 11, Sophie Alpert, a Facebook engineering manager who ran a major open-source project called React, made an announcement on Twitter: "today's my last day at Facebook."
In the tweet, which got 3,600 likes and elicited 247 comments, Alpert said she was leaving to join a start-up called Humu. But she neglected to tell her more than 41,000 followers the reason for her abrupt departure.
Four days earlier, Alpert, who identifies as transgender, provided that reason in an internal post viewed by CNBC. Alpert wrote on Workplace, Facebook's internal social network, that she'd been harassed by her colleagues after criticizing the lack of diversity at the company. Among other things, she said she'd been attacked on Blind, an anonymous workplace app.
"Facebook is good for many people, but it's not the right place for me right now," Alpert wrote. "I want to spend my time at a place willing to push further on diversity and inclusion. One where it's not OK to write on Workplace that white privilege doesn't exist. One where if I call out that our board has too many white men, I don't get harassed by other employees on Blind with transphobic messages saying I should be fired."
Facebook's diversity problem has been overshadowed in the past year by the bigger crises at the company related to user privacy and securing the platform against manipulation by foreign actors. With the stock down more than 15 percent in the last 12 months, CEO Mark Zuckerberg has his hands full dealing with concerned users, advertisers, investors and lawmakers.
Amid the turmoil, Facebook is also facing a mass exodus of talent, from the departures of the founders of Instagram and WhatsApp to security chief Alex Stamos.
As Alpert's case illustrates, at least some of it relates to core cultural issues. In November, Mark Luckie, an African-American manager who'd recently left Facebook, accused the company of having "a black people problem," and said that, "in some buildings, there are more 'Black Lives Matter' posters than there are actual black people."
Facebook, like most of its Silicon Valley peers, is mostly male and very white. Of the company's more than 30,000 employees, 36 percent were women, as of last year's diversity report, up from 31 percent in 2014. Women occupied 22 percent of tech roles last year, an increase from 15 percent four years earlier. Black employees, meanwhile, made up only 4 percent of the company in 2018, with those in technical and leadership roles having even less representation.
Facebook said the number of employees who identify as "LGBQA+ or Trans+" rose for a third straight year to 8 percent. The company also said it has "employee affinity groups" across the globe for LGBTQ and trans employees.
Alpert did not respond to requests for comment. Anthony Harrison, a spokesman for Facebook, said in a statement to CNBC that the company doesn't tolerate harassment and has "clear policies about how people should communicate with and treat each other at Facebook."
Harrison also provided a comment specifically about Alpert.
"Sophie is very aware of how serious we took her concerns given she spent significant time with members of our human resources team who worked in earnest to address the issues on Blind," he said. "Because the comments in question were made anonymously there we weren't able to find out who posted them."
Alpert's post resonated with some of her colleagues.
"It's sad to know that we still have to fight those battles against discrimination and bullying within our own walls, and even sadder to know that this situation is making great talent leave," one employee wrote in a comment.
Another wrote a post saying, "Really sad to see such a talented engineer and leader leave Facebook due to harassment and bullying. How do we stop this from happening?"
A human resources employee at the company responded in the thread, saying she would reach out to Alpert to "be sure we've reviewed all your concerns."
Alpert added a follow-up.
"Thanks for the offer," she wrote. "You and I already discussed these issues months ago when you said there wasn't anything HR could do, but I'm happy to discuss more if it would be helpful."
Within Facebook, complaints aren't all falling on deaf ears.
According to a report this week from Business Insider, Facebook has just announced a new "set of ground rules" for communication at work. Mike Schroepfer, Facebook's chief technology officer, wrote a memo laying out the three guidelines:
"Don't insult, bully, or antagonize others," the memo says. "Don't try to change someone's politics or religion. Don't break our rules about harassing speech and expression."
Alpert's conference session was posted on YouTube, where it's been viewed more than 35,000 times. The video evoked comments from people calling her a "thing in a dress," according to a tweet from Alpert on Oct. 27. Alpert said that as head of React, "this content wouldn't _exist_ without me. Would be cool if you respected me as a person too."