San Francisco: The way Tina Huang tells it, the path to her resignation from Twitter Inc was a Kafkaesque experience. She said she was denied a promotion, led to believe her coding skills were inferior, asked to take a leave of absence, and scolded for taking that leave.

Two years ago, she sued, contending that the company systematically thwarts the advancement of female engineers. Since then, she’s been gathering data on gender and pay for her peers there and says she can prove Twitter stacks the deck. By January, she plans to ask a state judge for permission to represent 133 female engineers at Twitter, in what would be the first group case of its kind in Silicon Valley if certified.

Huang said in an interview the time is ripe to do something that’s never been done before: pry open entrenched, male-dominated barriers in the technology sector. One catalyst, she said, was a February blog post by former Uber Technologies Inc engineer Susan Fowler, which detailed a predatory work environment, infighting, a “chaotic” organisation and blatant sexual harassment. That post helped lead to the founder and chief executive officer’s ouster.

“You not only saw real action happen at Uber but you also saw the amount of the conversation” that followed, Huang said. “Women were emboldened by it.”

Twitter has rejected Huang’s claims in court filings and in a statement — saying that she resigned voluntarily after being denied a second promotion and company leaders tried to persuade her to stay.

“Twitter is deeply committed to a diverse and supportive workplace, and we believe the facts will show Ms Huang was treated fairly,” the company said.

Larger narrative

Since the suit was filed, the dynamics have changed in Silicon Valley. In September, three women at Google sued the company in a class action, claiming it systemically pays male employees more than their female counterparts. Add to that a groundswell of women speaking out in the past few months with complaints against tech and venture capital companies alleging sexual harassment, underscoring the rocky terrain women face culturally and professionally.

“Hearing the stories from numerous other women has helped me understand how my incident, though unique in its details, is part of a larger narrative,” Huang said. “It’s basically impossible for any individual to know with 100 per cent certainty that her promotion was denied due to gender. The only way to understand the systemic bias is for all of us to share our experience so we can look at what’s happening on the whole.”

Huang joined Twitter eight years ago as one of its first engineers. In 2013, she was one of a number of people being considered for a promotion.

Engineers at Twitter are placed on a “technical ladder,” with an eight-rung hierarchy. When Huang joined the company, the ladder didn’t exist, but she was eventually slotted into the fourth rung. No woman had ever reached the fifth rung, yet it was a critical step because it’s where engineering jobs shift from coding and discrete projects to higher-level management.

Huang learnt she didn’t get the promotion in February 2014 and promptly told the chief executive officer at the time, alerting him to her concerns that the process lacked transparency and that she believed she was denied a promotion due to her gender. But it was hearing from a colleague that her coding, an engineer’s fundamental tool of the trade, was deemed inadequate that felt personal.

“Even though I knew it was bogus, it was a huge emotional toll,” Huang said. “It took years for me to recover confidence in my engineering and technical skills.”

Apple, Google

Before Twitter, Huang had worked at Apple Inc, where she helped develop the OS X operating system, and Google, where she worked on Google News. She left both companies on good terms, and as of January 2014, a few months before she left Twitter, was rated “exceptional” in a performance review.

Workers often have different experiences of bias, and courts reject class actions when the facts vary too much by individual, an argument Twitter has already made in an early attempt to rebut Huang’s case. But Huang’s lawsuit seeks to show the result of systemic discrimination — the impact — rather than detailing treatment.

“The principal difficulty the case will face is in judicial resistance to a story of discrimination that places responsibility on the organisation,” said Tristin Green, a professor at University of San Francisco School of Law who specialises in employment discrimination.

Green said Huang and her lawyers face an uphill battle if they “can’t convince a court to see the bigger picture of organisational involvement.”

Other women from Twitter who may join Huang’s case haven’t been identified in court filings, though some may submit statements to accompany her request for class-action status.

Black box

Huang describes Twitter’s promotion committee as a “black box.” Employees up for promotion don’t know who sits on it. There’s no input from workers, no interview, no feedback or explanation about the decision.

When Huang complained about discrimination, she says she was urged by human resources to take a week off while managers looked into the matter, and then placed on indefinite leave amid an investigation that became a “state of limbo” dragging on for weeks.

The turning point came at the end of April, when she met with Twitter’s head of engineering. Human resources had led her to believe the executive was reconsidering her promotion. Instead, Huang said, that person berated her for not being at work, clearly unaware that she was asked to go on leave months earlier. She also learnt her projects had been transitioned to other engineers.

“There was no intention of rectifying the situation,” Huang said. “They didn’t really want me back in the office.”

Twitter said in a court filing that Huang’s supervisor never suggested she take time off. While she vacationed, Huang’s manager asked her what he should tell colleagues and she confirmed “personal leave,” according to the filing.

The lawsuit against Google cites data from a 2015 review of the company by the US Labour Department, which in a separate federal administrative complaint found “systemic compensation disparities against women.”

Jason Lohr, Huang’s lawyer, thinks he can make a similar, evidence-based case. By using statistical samples to show how it takes women longer to be promoted or that there are fewer women being promoted, the lawsuit will focus on company policies that produce that outcome, he said.

Huang has since gone on to lead a start-up, Transposit, with an infusion of venture capital. What she’s learnt about how Twitter works since filing her lawsuit has convinced her that criticisms of the quality of her coding skills weren’t legitimate.

“I saw all the data, I saw all the feedback,” Huang said. “It was just used as an excuse.”

Lohr, Huang’s lawyer, says there’s safety in numbers. “You can’t turn to all women engineers at Twitter and say there’s a problem with all of them.”