Fleeing violence in his native Colombia, Felipe Salazar traveled to Miami in 2001 with his family on a visitor visa, hoping to get asylum, which was denied. This denial left him undocumented.
Still, Salazar earned both bachelor's and master's degrees in engineering from the Georgia Institute of Technology in Atlanta. But because he couldn't work legally in the US, Salazar didn't go on interviews or participate in internships like his classmates. He traveled everywhere by car, fearing airports because they might ask for his documentation.
All that changed in 2012, when then-President Barack Obama signed the Consideration of Deferred Action for Childhood Arrivals program, also known as DACA. The program allows some undocumented immigrants to get a work permit and relief from deportation. DACA recipients are often referred to as Dreamers, a nickname derived from earlier, unsuccessful legislation.
For Salazar, DACA meant a job.
"I finally had a stable salary," said Salazar, who works for Doppler Labs, a San Francisco startup that develops smart headphones.
Salazar's future, as well as the futures of about 800,000 young people who are part of the DACA program, is now in jeopardy. On Tuesday, President Donald Trump's administration officially rescinded DACA. Attorney General Jeff Sessions, who made the announcement at a press conference, said the phaseout will happen over the next six months.
The move ignores pleas to preserve DACA from tech leaders at Amazon, Apple, Facebook, Google and Microsoft and from members of his own party, including House Speaker Paul Ryan and Sen. Orrin Hatch.
"Dreamers are vital to the future of our companies and our economy. With them, we grow and create jobs. They are part of why we will continue to have a global competitive advantage," more than 300 tech leaders, including Apple CEO Tim Cook, Amazon CEO Jeff Bezos, Google CEO Sundar Pichai and Airbnb CEO Brian Chesky, said in an Aug. 31 group letter to Trump. "At least 72 percent of the top 25 Fortune 500 companies count DACA recipients among their employees."
That wasn't enough to dissuade the Trump administration. Sessions argued that the program represented an overreach of executive power, and urged Congress to take legislative action. The six-month transition period puts the pressure on Congress now.
"As the Attorney General, it is my duty to ensure that the laws of the United States are enforced and that the Constitutional order is upheld," he said during a press conference Tuesday. "Ending the previous Administration's disrespect for the legislative process is an important first step."
Sessions added: "Congress should carefully and thoughtfully pursue the types of reforms that are right for the American people."
Not long after that, Cook expressed dismay in an email to Apple employees that was obtained by CNET.
"I am deeply dismayed that 800,000 Americans — including more than 250 of our Apple coworkers — may soon find themselves cast out of the only country they've ever called home," Cook wrote.
In a Facebook post Tuesday, former President Barack Obama questioned Trump's move.
"Let's be clear: the action taken today isn't required legally. It's a political decision, and a moral question", Obama wrote. "Ultimately, this is about basic decency. This is about whether we are a people who kick hopeful young strivers out of America, or whether we treat them the way we'd want our own kids to be treated."
The DACA program will no longer accept applications for legal status after today. Existing DACA members who have a permit that's expiring now through March 5, 2018, can apply for a two-year renewal. (Get the full breakdown of the changes at CBS News.)
The effect on Silicon Valley
The impact of Trump's action on Silicon Valley is hard to estimate, in part because precise data on how many DACA recipients work in tech are hard to come by.
According to a 2015 report by the Institute for Immigration, Globalization and Education at the University of California, one-third of undocumented immigrants were majors in science, technology, engineering or mathematics, often shorthanded as STEM. This estimate, however, does not break down how many of those STEM majors are DACA recipients and does not reflect the fact some recipients of DACA, which can be obtained while attending high school, don't continue on to college.
The country needs more STEM professionals. In 2012, the President's Council of Advisors on Science and Technology warned the US could have a shortfall of nearly 1 million STEM professionals within 10 years. Todd Schulte, president of FWD.us, a collection of technology companies championing immigration reform, says Dreamers are already helping fill that gap.
"By any measure, the DACA program has been an overwhelming success for the entire US economy -- including Silicon Valley," Schulte said in an email. "DACA has allowed Dreamers to work in every industry and at nearly every single major company in America."
It's a sentiment echoed by the heads of the largest US tech companies.
"Dreamers have a special love for this country because they can't take living here for granted. They understand all the opportunities they have and want nothing more than the chance to serve their country and their community," Facebook CEO Mark Zuckerberg wrote in a post last week. "These young people represent the future of our country and our economy."
Critics say FWD.us and similar advocates are looking for cheap labor for the technology industry.
Still, Andres Donoso, a technology consultant at Accenture, only sees the benefits of DACA.
Donoso's parents brought him to the US from Ecuador when he was 4. He says it wasn't until he started to consider college that he realized he was undocumented. "I have an older brother and I knew something was wrong but I didn't understand until I had to sit down with my high school counselor," Donoso said from Boston, where he lives.
Donoso didn't qualify for in-state tuition, and other financial-aid options were out of his reach because of his legal status. A merit-based scholarship from New York University, another from the Society of Professional Hispanic Engineers and his parents' "immense sacrifice" allowed him to obtain two engineering degrees.
Now he helps his sister financially so that she can attend school. However, he couldn't have done this if it wasn't for the work permit he received under DACA.
This is a frequent problem among these young immigrants. Tuition standards and prices vary by institution. Some states have passed laws that allow these students to pay the same rates as US citizens at public universities. Also, there are scholarships that Dreamers can apply for.
The Trump administration's new policy leaves the future uncertain for those working in the US. Some may now have to leave the country. Yuriana Aguilar, a cardiovascular researcher, came to the US from Mexico when she was 5 years old. She is now a researcher in Chicago after graduating from a doctorate program at the University of California, Merced.
"I am actually very blessed that I have a lot of options in terms of work, in other countries," Aguilar said. "But I really want to stay here. This is the country I know, this is the country I grew up in and this is the one I want to give back to as a professional."
CNET's Maggie Reardon contributed to this story.
The Smartest Stuff: Innovators are thinking up new ways to make you, and the things around you, smarter.
CNET en Español: Get all your tech news and reviews in Spanish.