There's been a lot of talk about diversity in tech, but some are saying it's mere lip service.
One vocal dissenter is ex-Twitter engineer Leslie Miley, who says the chatter isn't being followed with meaningful action.
While tech firms like Twitter (TWTR), Apple (AAPL) and Facebook (FB) have released diversity stats for the past two years, they've shown little progress: The companies are still overwhelmingly white and male.
"Where else in technology can you see almost no movement at all -- and people think that is good?" said Miley, who now heads up the engineering department at startup Entelo. "It's a failure."
He went public about his experiences at Twitter, like having to advocate especially hard for diverse candidates.
"They're doing a lot of things that are externally focused so they have a good story. The public eats it up, the press eats it up. [But] there's not a lot of effectiveness inside the organization," said Miley.
"These are highly intelligent people. They get it. They know it's a PR piece versus something that's actually substantive," added Miley.
Twitter named a new head of diversity last month: Jeffrey Siminoff, a white man with ties to the LGBT community.
Miley said the hire was a "perplexing choice" -- and he wasn't the only one who thought so.
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Siminoff hailed from Apple, a company that hasn't been terribly impressive with its diversity efforts. Earlier this month, Apple's board rebuffed a proposal to make its senior leadership more diverse, saying it was "unduly burdensome and not necessary."
"Friends of mine (who will remain nameless) have left Apple because they were facing the same struggles surrounding working there that I felt at Google, that boil down to this: they didn't feel included and didn't feel like Apple really gave a damn about that," wrote Slack engineer Erica Baker in a Medium post.
Where Twitter received criticism, Pinterest was praised. In January, the firm added Candice Morgan, a black woman from Catalyst, as its first head of diversity.
But it's not enough to just hire a minority candidate for the role of diversity chief, according to Frank Dobbin, a Harvard sociology professor who studies diversity management.
He said in order for a company to be truly inclusive, it needs to have people from a diverse set of backgrounds across its entire leadership team.
Twitter's management in the U.S. is 78% male and 72% white. Siminoff's hire doesn't do much for the company's 2016 goal of increasing the roles of women and minorities in leadership. (Twitter did not respond to requests for comment.)
Related: Ex-employee blasts Twitter for diversity failings, rival firms come knocking
One of the most popular ways that companies say they're improving diversity is through employee training. A new study from the Harvard Business Review found that diversity training -- at least on its own -- could actually be another example of optics over action.
White men in charge can actually be even more blind to racism and sexism after diversity training, the study found. It can also result in women and minorities feeling as though they're being treated fairly even when they're not.
Silicon Valley companies need to take a deeper, more thorough approach to hacking diversity. After all, a diverse workforce makes companies more likely to outperform financially.
"We are supposed to be the smartest people in the room," added Miley. "Are you really telling me you can't find minority candidates and increase the gender ratio?"
