India’s engineers have thrived in Silicon Valley. So has its caste system.

Whenever Benjamin Kaila, a database administrator who immigrated from India to the United States in 1999, applies for a job at a U.S. tech company, he prays that there are no other Indians during the in-person interview. That’s because Kaila is a Dalit, or member of the lowest-ranked castes within India’s system of social hierarchy, formerly referred to as “untouchables.”

Silicon Valley’s diversity issues are well documented: It’s still dominated by white and Asian men, and Black and Latino workers remain underrepresented. But for years, as debates about meritocracy raged on, the tech industry’s reliance on Indian engineers allowed another type of discrimination to fester. And Dalit engineers like Kaila say U.S. employers aren’t equipped to address it.

In more than 100 job interviews for contract work over the last 20 years, Kaila said he got only one job offer when another Indian interviewed him in person. When members of the interview panel have been Indian, Kaila says, he has faced personal questions that seem to be used to suss out whether he’s a member of an upper caste, like most of the Indians working in the tech industry.

"They don't bring up caste, but they can easily identify us," Kaila says, rattling off all of the ways he can be outed as potentially being Dalit, including the fact that he has darker skin.

The legacy of discrimination from the Indian caste system is rarely discussed as a factor in Silicon Valley's persistent diversity problems. Decades of tech industry labor practices, such as recruiting candidates from a small cohort of top schools or relying on the H-1B visa system for highly skilled workers, have shaped the racial demographics of its technical workforce. Despite that fact, Dalit engineers and advocates say that tech companies don't understand caste bias and have not explicitly prohibited caste-based discrimination.

In recent years, however, the Dalit rights movement has grown increasingly global, including advocating for change in corporate America. In June, California's Department of Fair Employment and Housing filed a landmark suit against Cisco and two of its former engineering managers, both upper-caste Indians, for discriminating against a Dalit engineer.

After the lawsuit was announced, Equality Labs, a nonprofit advocacy group for Dalit rights, received complaints about caste bias from nearly 260 U.S. tech workers in three weeks, reported through the group’s website or in emails to individual staffers. Allegations included caste-based slurs and jokes, bullying, discriminatory hiring practices, bias in peer reviews, and sexual harassment, said executive director Thenmozhi Soundararajan. The highest number of claims were from workers at Facebook (33), followed by Cisco (24), Google (20), Microsoft (18), IBM (17), and Amazon (14). The companies all said they don’t tolerate discrimination.

And a group of 30 female Indian engineers who are members of the Dalit caste and work for Google, Apple, Microsoft, Cisco, and other tech companies say they have faced caste bias inside the U.S. tech sector, according to a statement shared exclusively with the Washington Post.

The women, who shared the statement on the condition of anonymity for fear of retaliation, argue that networks of engineers from the dominant castes have replicated the patterns of bias within the United States by favoring their peers in hiring, referrals, and performance reviews.

"We also have had to weather demeaning insults to our background and that we have achieved our jobs solely due to affirmative action. It is exhausting," they wrote. "We are good at our jobs and we are good engineers. We are role models for our community and we want to continue to work in our jobs. But it is unfair for us to continue in hostile workplaces, without protections from caste discrimination."

The tech industry has grown increasingly dependent on Indian workers. According to the State Department, the United States has issued more than 1.7 million H-1B visas since 2009, 65 percent of which have gone to people of Indian nationality. Close to 70% of H-1B visa holders work in the tech industry, up from less than 40% in 2003, says David Bier, an immigration policy analyst at the Cato Institute.

Devesh Kapur, a professor of South Asian studies at Johns Hopkins University, found that in 2003, only 1.5 percent of Indian immigrants in the United States were Dalits or members of the lower-ranked castes.

The lawsuit, which was initially filed in federal court before being refiled in October in state court in Santa Clara County, where Cisco is headquartered, alleges that Cisco violated the California Fair Employment and Housing Act, which prohibits employment discrimination based on race, religion, national origin, and ancestry.

The immigration status of Dalit workers, including visas and green cards that require being sponsored by their employers, made it difficult for them to speak out against the discrimination they allege, says Soundararajan from Equality Labs, which is conducting a formal survey to follow-up on the claims they received this summer.

"Just like racism, casteism is alive in America and in the tech sector," said Seattle-based Microsoft engineer Raghav Kaushik, who was born into a dominant caste but who has been involved in advocacy work for years. "What is happening at Cisco is not a one-off thing; it's indicative of a much larger phenomenon."

In a statement, Cisco spokesperson Robyn Blum said: "Cisco is committed to an inclusive workplace for all. We have robust processes to report and investigate concerns raised by employees which were followed in this case dating back to 2016, and have determined we were fully in compliance with all laws as well as our own policies. Cisco will vigorously defend itself against the allegations made in this complaint."

Dalit engineers said that most Indian workers from upper castes do not seem aware of their caste privilege and believe caste bias is a thing of the past, despite the fact that high-profile tech CEOs and board members, such as Microsoft CEO Satya Nadella and Amazon board member Indra Nooyi, the former CEO of Pepsi, are Brahmins, or members of the highest caste.

In a statement, Facebook spokesperson Nneka Norville said: "To build services for the whole world, we need a diverse and inclusive workplace. We train managers to understand the issues team members from different backgrounds may face and have courses to help employees counter unconscious bias."

Apple spokesperson Rachel Tulley said: "At Apple, we are dedicated to providing employees with a workplace where they feel safe, respected, and inspired to do their best work. We have strict policies that prohibit any discrimination or harassment, including based on caste, and we provide training for all employees to ensure our policies are upheld."

Google spokesperson Jennifer Rodstrom said: "Our policies prohibit harassment and discrimination in the workplace. We investigate any allegations and take firm action against employees who violate our policies."

Microsoft spokesperson Frank X. Shaw said there are no official complaints of caste bias at Microsoft in the United States. IBM and Amazon declined to comment. (Amazon chief executive Jeff Bezos owns the Washington Post.)

Caste is often discovered through questions, not always through appearance. (Although Dalits may have a darker complexion, skin color is not synonymous with caste.) Questions about whether someone is a vegetarian, where they grew up, what religion they practice or who they married may be used as a “caste locator,” seven Indian engineers working in the United States said in interviews with the Post, unrelated to the statement shared by 30 female Indian engineers.

Other tests include patting an Indian man on the back to see whether he is wearing a "sacred thread" worn by some Brahmins, the highest-ranked caste. (This gesture is sometimes referred to as the "Tam-Bram pat," in reference to Tamil-speaking Brahmins.)