"For the longest time while I was inside, my biggest fear was what's life going to be like for me after prison, who was going to give me a chance? I was going to have this stigma of being an ex-felon," he told CNBC recently.

Schuhmacher said he has no plans to be the first, and the coding skills he learned while behind bars have already laid the groundwork for a career outside prison walls. But finding his way to his current job at Fandom, an entertainment site where super-fans can read and post content on everything from "Game of Thrones" to "Pokemon," has presented challenges of its own.

Despite the technical hurdles, some graduates of the program have found real-world success in a competitive industry after leaving prison, and of the twenty-or-so alumni who have been released, none have returned.

Founded by venture capitalist Chris Redlitz and his wife Beverly Parenti, The Last Mile costs roughly $200,000 per year to run, and is funded privately and with the sale of prison products like license plates. At the five facilities where it currently operates, the program has the unique challenge of teaching inmates — some of whom have been incarcerated since before the dotcom boom — how to code on computers that aren't even connected to the Internet.

Schuhmacher's transformation from convict to coder is a radical shift for a man who spent so many years in jail. It's also a standout success story for nonprofit The Last Mile, which teaches computer coding to inmates at some of California's toughest prisons.

Today, just months after his release, Schuhmacher blends in with the Silicon Valley crowd as a software engineering intern at a bustling tech firm, ditching his blue prison uniform for a sweater and khakis, and his cell for a cubicle.

We in general in the company didn't know how the company at large would react to it. Do I want somebody with Chris's background sitting next to me, working with me?

Schuhmacher's chance came when Jon-Paul Ales-Barnicoat, Fandom's vice president of employee experience, paid a visit to San Quentin to evaluate The Last Mile as a potential partner for the company. "I'd never been to prison before. It was scary," Ales-Barnicoat said.

"The thing that really struck me more than anything is there's these giant walls with some of the best real estate in California and you don't see the horizon," he said. "I couldn't imagine living in a world where you couldn't see the horizon."

Ales-Barnicoat eventually met Schuhmacher, who stood out among the program's participants. "He was so engaging...and really proud to show his work, and he had done some really good design work as well, and we just connected," he said. "So when he got out it was really a no-brainer."

After his release from prison, Fandom brought Schuhmacher in for an interview. "They set up a four hour interview process with the entire development team," Schuhmacher said. "I'm not going to say it was as hard as the parole board, but it was pretty tough."

Fandom's CEO Craig Palmer said he initially had some reservations about hiring a former inmate. "We in general in the company didn't know how the company at large would react to it," Palmer said. "Do I want somebody with Chris's background sitting next to me, working with me?"

But Palmer said Schuhmacher's time in prison gave him a unique outlook, different from a college student who would apply for a similar role.

"I think from a technical skill set it's very similar, but from a life experience perspective it's very different," he said. "I think he brings a little of life experience that's far greater than a typical intern. And I think it's actually an advantage for him."

Ultimately Schuhmacher was given a one-year internship, and Palmer said his employees have responded well to that decision. "Actually people have said they're really proud to work at a company that gives someone like Chris a chance," he said.

Bartosz Bentkowski, a senior engineer who works directly with Schuhmacher, said he was "a little afraid" when he first heard about the new intern, "but it turned out great." "He has a completely different viewpoint on the things we do, and that's pretty great for me because it changed my perspective on some of the things we're doing," he said.

Apart from his internship at Fandom, Schuhmacher is currently working on a start-up he dreamed up while still in prison called "Fitness Monkey," an online platform which promotes addiction recovery through physical fitness and logs users' "clean time" and workout metrics. Schuhmacher said he has partnered with Santa Clara University to develop the company, and that the platform has generated interest from a Silicon Valley startup accelerator.

One big question that Schuhmacher, and The Last Mile as a whole, has faced: Why should resources, connections, and opportunities be given to convicted felons — particularly in a city where job competition is fierce?

Schuhmacher said that "of the men in prison, 90 percent are going to get out one day… do you want somebody that went to prison, didn't do anything with their time, spent all day in the yard doing push-ups, or do you want somebody that really took accountability for their situation?"

The Last Mile co-founder Beverly Parenti shared a similar message. "They're going to be in your communities, they're returning to their families. Who do you want them to be?"

As he approaches his first full year as a free man in two decades, Schuhmacher said he hopes to share what he has learned and help others set their lives on a better track. "Coming back into society, I can take everything I learned and share it and pay it forward," he said. "And I feel like that's my responsibility."