(Bloomberg) —Tracy Chou wrote a post on Medium in October 2013, challenging tech companies to tell the world what percentage of their software engineers were women. Surprisingly, it worked: Google, Apple, Facebook and others published their lopsided race and gender statistics, and Chou, then a Pinterest software engineer, became a face of the tech diversity movement. Pinterest positioned itself as a company working hard to hire more women as well as black and Latino workers. In 2015, the company made an unprecedented move: It published a set of diversity-focused hiring goals. It would strive to make 30 percent of its engineering hires women, and it would report on its progress in a year.

Sixteen months later, Pinterest retreated. Despite all its efforts, only 22 percent of its new engineers were women, and in response, the company lowered its goal for next year from 30 percent to 25 percent. It had hit and exceeded its targets in two other categories — making 8 percent of its engineering hires under-represented ethnic minorities, for example. Pinterest said it missed its women in engineering goal because it focused on hiring more senior women, which takes longer. But its admission that it had missed its mark and would lower expectations was a disappointment. “Obviously we were all hoping it would be better and closer to 30 percent,” said Chou, who left the company in June. Pinterest’s head of diversity, Candice Morgan, said the company sets goals that are challenging and that it thinks it has a 70 percent chance of reaching.

Pinterest’s big goal — and its later retrenchment — show how tech companies’ diversity ambitions can come with their own set of messes and challenges. In the two years since tech giants first revealed how most of their employees were white and Asian men, their diversity has only increased a few percentage points – or, in some cases, dropped. Most companies’ first response was to try to make their hiring processes more “blind”:  stripping resumes of names and pictures, for example, to keep out information that might unintentionally bias an interviewer for or against a candidate.

Now, some companies want to do more than cover their eyes. It’s not enough to just publish demographic data and scrub names and pictures from resumes. Unlike other companies, Twitter and Pinterest set specific hiring goals. Facebook rewarded its recruiters extra for “diversity hires.” Microsoft is tying managers’ bonuses to their diversity hiring after the proportion of female workers fell for two consecutive years. Even small startups – like Penny, a four-person personal finance company in San Francisco that’s the subject of the latest episode of Bloomberg’s Decrypted podcast – are evaluating candidates on whether they bring a new perspective to the team, in addition to their technical skills. Some companies are embracing affirmative action hiring, even if they are careful to call it something else.

“I have quite a few clients saying, ‘We want to take it one step further,’ or saying, ‘Listen, we did the unconscious bias thing, and we didn’t get a lot out of it,’” said Y-Vonne Hutchinson, a diversity consultant who works with startups and helped found Project Include, a group of diversity advocates who publish guides of best practices for companies. “It’s happening in a way that wasn’t happening last year.”

Hutchinson encourages companies to explore new tactics, but she also warns them to prepare for resistance. “Affirmative action gets a lot of blowback, but it was one of the most successful ways of getting people from under-represented groups into jobs and institutions they were excluded from,” Hutchinson said. She’s African-American, and she said affirmative action helped her mother get a federal government job. “I don’t think tech has embraced affirmative action because they’re really married to the idea of a meritocracy.”

Instead of calling it “affirmative action,” companies are looking for a policy that “looks like that, talks like that, but isn’t perceived as that,” Hutchinson said. Companies want to discuss equal opportunity without the terms “quotas” and “affirmative action,” she said.

Should tech companies ignore a candidate’s background when deciding whether to hire them – or should they factor it in? The debate is ongoing, said Chou, who is also part of Project Include. (She said she left Pinterest not out of disappointment, but because she wanted to try something new.)

It’d be cleaner and easier if making the hiring process blind suddenly led to more women and minorities being hired, but that’s often insufficient, Chou said. Active policies to promote diversity, on the other hand, can strike some job candidates as unjust. “People feel it’s an unfair judgment on them if they get turned down and someone they feel is objectively less than them in some way is hired,” she said.

At Pinterest, the pressure of reporting public hiring goals could be felt inside the company. “That internal conversation — ‘We’re not going to hit this, and it’s going to look really bad if we don’t’ — made people haul ass and get their shit together,” Chou said. Morgan, Pinterest’s head of diversity, wrote in an email: “Setting public goals focused and encouraged the team to have more authentic conversations and learn more about how to make meaningful progress … They’ve resulted in the most diverse team Pinterest has had to date.”

Pinterest asked some of its employees to recommend a certain number of candidates from under-represented groups for jobs at Pinterest, and some workers felt those goals were unfairly distributed, Chou said. Some employees pushed back when they were encouraged to refer the same number of people as a larger team and asked if the referrals should be prorated, she said. “It was a little frustrating to hear the grumblings but also not that surprising, as people tend to grumble about any extra work that they’re asked to do,” Chou said. Morgan said the company later tailored its requests based on feedback from engineering leaders.

At Facebook, recruiters in 2015 were told to prioritize finding “diversity candidates” — engineers that weren’t white or Asian men, according to former recruiters who asked not to be identified because they were not authorized to talk about their work. After a few months, the recruiters became frustrated, because they said most of their minority engineering candidates didn’t end up getting an offer. From 2015 to 2016, the number of women in technology roles at Facebook increased 1 percent, and its proportion of black and Latino workers stayed flat. Two former recruiters blamed the engineering department’s hiring process, which gave veto power to a small group of engineering leaders that signed off on every offer. Though Facebook pushed recruiters to look for diversity, those making hiring decisions were not held accountable to those same goals, according to the former recruiters.

Even when the hires are made, other employees may grow resentful. GitHub, a site where coders can store and share their work, hired consultant Nicole Sanchez in 2015 to create and lead its Social Impact team, which focuses on improving diversity efforts. The team is now 11 out of the company’s 600 employees, and it pushed strongly for more diversity among the people who interviewed job seekers, the company said.

Some employees groused. Two former GitHub employees said the Social Impact team would question hiring practices and choices and ruled with a heavy hand. The former employees, who declined to be identified out of fear of reprisal from the company, also alleged that GitHub sometimes missed out on the best talent by focusing too much on a candidate’s background. A GitHub spokeswoman declined to comment.

When tech companies talk about hiring, they often talk about bringing in “the best person possible” and ignoring everything else. For many, “best” has meant the person who’s most technically skilled or who will be shipping code the soonest after they start.

But some are redefining “best” to factor in diversity. At Penny, which builds a chatbot that texts users analysis and advice about their spending, Chief Executive Officer Mitchell Lee wanted the company’s fifth hire to add diversity to the team. He spent the fall looking for candidates who were different from the four men who already worked there – affirmative action hiring, in his own words.

“When I say affirmative action, I mean I want to be able to see someone’s picture,” Lee said. If asked to choose between two hypothetical candidates who are equally qualified for a job at Penny, then he rejects the premise as false: Those two people are not equally qualified. “Somebody with a diverse background and a totally different perspective is more qualified for the position we’re trying to fill, which is expanding upon the collective viewpoint of what Penny has,” he said.

Lee found that some candidates were dropping out of the interview process along the way, and they were often those he was particularly interested in – women or people with unusual backgrounds. He started checking in with those candidates more frequently, encouraging them along the way. It helped. But he said it showed him how much more was needed beyond getting diverse candidates in the mix: He needed to earn the trust of many of them. “It’s really hard to convey, especially if you’re like me and you’re a white guy in his mid-twenties trying to tell candidates that diversity is something you care about,” he said.

In December, after several months of searching – Lee estimates he looked through hundreds of candidates — Penny hired a fifth person, Vertika Srivastava, an Indian-American woman who went to the University of Michigan and worked as a software developer at Accenture. The four current employees are excited for her to start. But Lee and the other Penny workers — they all had a say — waffled when deciding whether to give her an offer. Penny’s developers code mostly in Ruby, a programming language Srivastava doesn’t have much experience in.

At one point during the interview process, Srivastava asked the four Penny guys why they were interested in her. They listed some aspects of her personality, and they were blunt: It was also because she’s a woman. “I liked that they didn’t tiptoe around that,” she said. She starts this week.

Penny’s approach is different than that of most companies. Pinterest and Twitter don’t talk about quotas; they talk about hiring goals. Stacy Brown-Philpot, the African-American CEO of TaskRabbit, an on-demand job platform, has pledged to make the company’s workforce represent the ethnic and racial makeup of the country. She said on stage at a conference in October that in order to get there, the company will need to “over-index” on certain groups, though she followed that up with: “I don’t know if I would say it’s affirmative action.”

Slack, a $3.8 billion workplace chat service startup, practices “intentional hiring,” said Leslie Miley, its director of engineering and a diversity advocate. The company actively looks for people outside of “the standard 20 schools and six companies,” he said, and they “value what historically hasn’t been valued in Silicon Valley.” That means measuring people by “distance traveled” — how far they’ve come in life instead of just looking for a Stanford computer science degree. Miley said that candidates who would score higher on this metric could include those who were the first in their family to go to college, or are veterans, or went to community college.

But Miley dislikes the term “affirmative action.” “The amount of baggage attached to that term is horrid,” he said. “When you say ‘affirmative action,’ the very next question most people have is, ‘Are we going to lower the bar?’ So let’s not call it that. Let’s call it ‘hiring the way hiring always should have been.’ What I want is a level playing field.”

—With reporting by Eric Newcomer