Twitter became the latest big name in tech to be hit with a gender discrimination lawsuit, when former employee Tina Huang filed a proposed class action suit against the company last week alleging that the way the social media company promotes people in technical roles effectively discriminates against women.

Engineering roles at the company are split up into a "ladder" of eight job titles, according to the suit — but the requirements for moving up that ladder and actual openings aren't advertised, instead upper management uses a mysterious "shoulder tap" process to let certain employees know about opportunities.

And whether the company realizes it or not, this leads to a bias towards dudes, the suit alleges. (Twitter, for its part, told the Post that Huang was "treated fairly.")

It's no secret that tech has a gender problem — and Twitter is no exception. According to diversity figures released by the company last year, 70 percent of Twitter employees are male. And things are even worse in leadership and technical roles: Women make up just 21 percent of leadership and 10 percent of those in technical jobs.

That plays into the alleged discrimination at Twitter, according to text from the lawsuit published by Mashable.

Promotion into Twitter’s senior technical positions is based on subjective judgments, by committees that are comprised of and dependent on upper management at Twitter, and predominantly male. These judgments are tainted with conscious or unconscious prejudices and gender-based stereotypes, which explains why so few women employees at Twitter advance to senior and leadership positions.

Essentially, the allegation is that there's a feedback loop leaving women at a disadvantage at Twitter: The people making decisions about who should be promoted are men, and the people they're choosing to promote are more of the same.

The idea that people might be biased towards people like them is hardly a radical: Some academics have even argued that favoritism towards people within an individual's own group is a more likely cause of most modern discrimination than active malice towards people with different backgrounds. Looking for things like a "culture fit" may seem innocuous to the people in charge of hiring or promotion — but ultimately can lead to companies hiring a bunch of people with the same life experiences as current employees at the expense of other candidates with different and potentially important perspectives.

And the lack of diversity in tech means such "ingroup favoritism" could have particularly pernicious outcomes for the industry where, despite a myth of meritocracy, who you know can play a big part in getting your foot in the door.

Tech heavy fields like network security and computer software are among the areas where personal connections matter the most for hiring, according to a recent analysis of hiring and network data about its users by professional networking site LinkedIn.

So women and racial minorities are already at a disadvantage because they're under-represented in tech in the first place — which means they might have a harder time establishing the same kind of network as people who share more superficial similarities with the decision makers already in place at big tech companies.

But even if they manage to land a job, lawsuits like the one against Twitter and a similar suit against Facebook allege that female employees face an uphill battle inside companies to have the same opportunities as their male counterparts — and they're fed up with it.

Huang, the woman behind the Twitter suit, was a longtime employee of the company, working in a variety of software engineering roles starting in 2009 until she left in June of last year. According to the suit, Huang sent an e-mail to Twitter CEO Dick Costolo in March of 2014 detailing complaints about the promotion process after years of frustration — and was put on leave while the company investigated.

"After three months without explanation as to the status of the investigation, or mention of any possible time frame for her return to work, she felt she had no choice but to leave the company for the sake of her career," the suit said.

Twitter said it was her decision to leave. "Ms. Huang resigned voluntarily from Twitter, after our leadership tried to persuade her to stay. She was not fired," a spokesperson for the company said in a statement. "Twitter is deeply committed to a diverse and supportive workplace, and we believe the facts will show Ms. Huang was treated fairly."

Huang clearly disagrees — and is inviting "all current and former female employees of Twitter denied promotions in the three years prior to the filing" of her complaint to join her in a class action suit.