One by one, the entrepreneurs, clad in crisp blue jeans and armed with PowerPoint presentations, stood before investors and tech bloggers to explain their dreams of changing the world.
For these exuberant times in Silicon Valley, the scene was familiar; the setting, less so.
With the young and ambitious flocking again to northern California to launch internet companies, there were signs one recent morning that start-up mania has taken hold even behind the faded granite walls of California's most notorious prison.
"Live stream has gone mainstream. Mobile video usage went up and is expected to increase by 28 per cent over the next five years," said Eddie Griffin, who was pitching a music streaming idea called At the Club. He happens to be finishing a third stint for drug possession at San Quentin State Prison, near San Francisco, after spending the past 15 years behind bars.
Mr Griffin was one of seven San Quentin inmates who presented start-up proposals on "Demo Day" as part of the Last Mile programme, an entrepreneurship course modelled on start-up incubators that take in batches of young companies and provide them courses, informal advice and the seed investments to grow.
According to the business news website Xconomy, incubator programmes have tripled in number for each of the past three years, a pace that has fuelled talk in tech circles of an "incubator bubble".
Chris Redlitz, the local venture capitalist who founded Last Mile, says that his goal was never to seek out a genuine investment opportunity inside a prison, but to educate inmates about technology entrepreneurship.
Inmates, after all, are not allowed to run businesses. They do not have access to mobile phones and they use computers only under close supervision.
After his presentation in San Quentin's chapel, which received a rousing reception, Mr Griffin told a reporter that it was unlikely he would launch his start-up idea immediately after being released this summer.
"I still have a lot to learn," he said. "I've never used a cellphone. Technology is kind of foreign in this environment."
But to hear San Quentin's inmates use jargon such as "lean start-up" and "minimum viable product" shows how start-ups have come to embody mobility, ambition and hustle.
"If they were doing this in the '80s there may have been a different theme or model," said Wade Roush, Xconomy's chief correspondent. "But in this day and age, becoming an entrepreneur or starting a business is a form of self-actuation."
Situated on prime waterfront land, San Quentin prison is home to California's only death row. But it has also kept a long-standing progressive reputation, boasting a college degree-granting programme and arts courses.
The Last Mile accepted 10 inmates out of 50 applicants for its latest batch. The programme, which graduated its first class of inmates last year, meets twice a week to discuss start-ups and lasts six months, although the most recent class took seven months because of a prison lockdown last year.
Some Last Mile participants, under official supervision, have also joined the online question-and-answer site Quora to respond to questions about prison life or describe what it felt like to commit murder.
The latest batch of start-up ideas included a fitness app that would motivate drug addicts to exercise, a cardiovascular health organisation, a social network for sufferers of post-traumatic stress disorder, a food waste recycling programme, and an e-commerce site for artists in prison.